Sutekus 4MOA Dot Sight M3 Type Review

I'll be reviewing the Sutekusu 4MOA red dot sight, a very cheap red dot sight sold on Amazon.

As far as I can remember, for the past 5-6 years or so, I've often seen several optical devices being sold on Amazon at extremely low prices (under 3000 yen), and I frequently came across the brand Sutekusu, which piqued my interest.

This time, we'll start by investigating what "sutekusu" means and then review a red dot sight.

Sutekusu

Sutekusu appears to be a brand called "Sutekusu," and it seems to be operated by a Japanese company called Tokai Co., Ltd.

I apologize for saying this, but I had mistakenly thought it was just one of those Chinese products that somehow ended up in Japan through some unclear process, which is common in the airsoft industry.

Upon further investigation, it appears that they operate the Naturehike brand, which offers affordable tents and sleeping bags; the Chinese outdoor brand MOBIGARDEN; and HABOBest, which installs injection molding machines for resin products and provides inspection equipment.

In all of these fields, they seem to have a fairly good reputation and are quite well-known for importing and selling cost-effective Chinese products (especially outdoor products such as camping gear).

Among these companies, there seems to be Sutekusu, which offers survival game equipment at affordable prices.

As far as I knew, the only thing they had was red dot sights, but after doing some research, I found they had a decent selection of items, from BDUs and boots to gun cases and Magpul CTR compatible stocks (all at surprisingly low prices).

Examples of airsoft gear from the Sutekus brand.

I had unknowingly been using CTR stocks for a long time.

It might be due to my lack of knowledge, but I didn't get the impression that it was a brand well-known in the military and airsoft communities, and it wasn't one of those dubious items often found in those areas (my apologies for the misunderstanding).

Far from being suspicious, it's a brand operated by a Japanese company, Shishigaki Co., Ltd., and some products even come with a one-year warranty, so it's a well-established brand that you can buy and use with confidence (it might even be more reliable than some fairly well-known brands).

Opened

This item was purchased several years ago and has been sitting unused ever since, so it may be slightly different from the latest model, but from what I can see on the sales website, it's almost identical.

First, let's look at the outer box.

The outer box is quite simple yet has a luxurious feel to it.

Let's open it and check the contents.

This set is basically usable with just the included accessories. As I will explain in more detail later, you will need a flathead screwdriver or a coin to adjust the position of the dot, so strictly speaking, you will need to prepare some other items as well.

According to the sales website, the latest model comes with a Japanese instruction manual.

One thing that personally impressed me about the packaging was how carefully it was done, despite the very low price.

appearance

Let's start by looking at the exterior from the front (objective lens).

The objective lens has a diameter of approximately 28 mm. The objective lens has a silver coating. More details about the lens will be provided later.

This is an eyepiece lens.

The eyepiece lenses appear to have a very clear tint. More details will follow.

This is the top view.

The material is aluminum.

All the controls (up/down/left/right adjustment, power) are visible. The rail mount is a fairly robust one with six tightening points.

This is the bottom view.

The rail connection points use the standard large hexagonal nuts.

It's on the left.

The mount height is a medium type.

It's on the right.

You can see a large power dial.

I placed it in the palm of my hand to get a sense of its overall size.

It's a fairly large size.

These are the specific dimensions.

The tube diameter is 30mm, which is a common size for tube-type red dot sights, so if you want to change the mount, there should be many compatible options available.

It's the weight.

It's fairly heavy at 275.5g.

It's generally large and heavy. Its external shape is quite similar to the Aimpoint M3. Historically, it was frequently used during the Iraq War and the early stages of the Afghanistan War, so many people have probably seen it in news photos and videos (the Aimpoint M3 and ACOG were standard equipment; currently, the Aimpoint M4 is used).

Therefore, I think it's a shape that matches M4-type rifles that have a triangular gas block that also serves as the front sight, like those used by regular soldiers, not special forces.

Mechanism and Function

I attempted to disassemble it to examine its mechanism and internal structure, but I gave up because it uses a special ring screw like the one shown in the photo below.

Because it uses the ring screw shown above, repairing it in case of malfunction requires some ingenuity. However, since the main unit costs less than 3000 yen and is quite robustly built, I don't think there will be many situations where you'll need to disassemble it.

I was able to understand the mechanism without disassembling it, so I will explain it.

The light-emitting unit is attached to a ring-shaped component, which is supported by a spring and screws for adjusting the up, down, left, and right positions. Turning these screws moves the ring, thereby changing the position of the dot.

I've also included photos without explanations below, so please compare them.

In my experience, this type (tube shape) allows for a larger adjustment range for the dot, so problems like being unable to zero in are less common even with cheap dot sights. Smaller types, especially replicas of the Eotech shape, tend to have tighter vertical adjustment ranges, so caution is advised (the genuine article has a completely different mechanism).

Remove the cap and insert the batteries.

The cap also serves as the power source.

The cap has an O-ring and appears to be waterproof, but the manufacturer doesn't advertise it as waterproof, so it's probably best to avoid getting it wet. However, I think very few people play airsoft in the rain in Japan, so it shouldn't be a problem (it would just damage the airsoft gun).

This is the dial for adjusting up, down, left, and right.

It's great that both caps have a rubber band to prevent them from getting lost, which also serves as a waterproofing measure.

You'll need a flathead screwdriver or a coin to adjust it. Both tools click when you turn the screw, making adjustment quite easy.

It does have markings, which probably represent the mill size, but since it's a low-priced item, I don't think you can rely on them.

How the lens and dots appear

Let's start by looking at the objective lens.

The lens has a silver coating, which appears to be intended to reduce reflections. The objective lens diameter is 28mm.

This is an eyepiece lens.

It is quite transparent. Many red dot sights have a blue coating on the eyepiece lens to allow red light to pass through easily, making the dot easier to see even in bright sunlight (such as in a desert), but this product does not have such a coating.

However, in the Japanese airsoft environment, such scorching hot conditions are rare, and clear lenses are preferred, so this shouldn't be much of a problem.

This is lens distortion.

There is a slight distortion in the lens at the top. Since it's not a scope, I don't think it's a major issue.

Let's light up the dots.

The dot switch is activated by turning the dial shown in the photo below, and there are 10 different options in total: red 1-5 and green 1-5.

Let's actually light up the red 1, 3, and 5, and the green 1, 3, and 5 to confirm.

Red Level 1

I think it's too dark to be very useful.

Red Level 3

Red Level 5

Green Level 1

Green Level 3

Green Level 5

The dots are clearly visible in the photo, but in reality they appear slightly blurred (partly due to my astigmatism). The brightness of the dots is too dim at level 1, so you'll probably end up using the maximum level 5.

Also, the actual dot is dimmer than it appears in the photos, and I feel it could use a bit more brightness. However, the battery is a sample and old, so a new one might be a bit brighter.

Next, let's try moving the dots up, down, left, and right.

The dots are clearly visible in all directions—up, down, left, and right—and the image is effective all the way to the edges of the lens, which is excellent. With some Chinese replicas, even those costing around 1 yen can have dots that are cut off.

This is how the dots look outdoors (red level 5, maximum; cloudy outside).

The cloudy weather outside makes the dots easy to see, but they are clearly visible even outdoors.

Actual usability and installation examples

In actual use, it is mounted on the XM177E1.

The XM177E1 has a fixed carrying handle and a high sightline, so I've changed the mount to a low mount. If yours has a detachable carrying handle, the height of the mount included with the product should be fine.

Chronologically, the XM177E1 was developed in the mid-1960s, so an M3-type red dot sight doesn't quite match, but since the airsoft gun is an Abu Dhabi Carbine (M727) and the sights resemble those of an M2, it looks like something out of Black Hawk Down's Delta Force, so I like using it.

When actually using it in the field, zeroing is perfect at around 30m, and I have almost no complaints. The dot seems a little dim, but that doesn't cause me to lose sight of it that often.

However, since I prefer forest fields, I might want more light if I were using a riverbank field in the scorching summer sun.

Summary

Even though it sells for under 3000 yen, it's perfectly usable and I think it's an excellent product for a first red dot sight.

Especially at first, I think this is an excellent product for getting used to using a red dot sight, rather than buying something mediocre at a low price and ending up with a dud.

It has a wide range of adjustment for zeroing, is easy to operate, has a typical tube shape, is made of metal and has a sturdy, robust construction, and although not explicitly stated, it appears to have some water resistance when viewed in person. Its incredibly low price makes it ideal as a first red dot sight.

Unless you have a strong preference for a specific shape or dislike the M3 type's design, I think you'll be more satisfied than dissatisfied.

The downsides include its large size, weight, and slightly dim pixels, but considering the price, these are not really issues to complain about.

That concludes my review of the Sutekusu 4MOA red dot sight.

Sutekusu 4MOA Red Dot Sight
It offers incredible value for money.

I've also reviewed other red dot sights, so please check them out if you're interested!