Tokyo Marui Velocity Reducer (Black)

I've heard about the velocity reducer for some time, with mixed reviews about how effective it is, and effect on accuracy and hop up. I want to play more indoors, without changing springs all the time on my m15a2. So, here is the data.

Background... My CA m15a2 has a systema tightbore and aluminum piston head, with a prometheous 120 spring. I left the hop up off for the velocity tests, since most guns have to be crono'd that way, and was using Airsoft Elite 0.20 gram bb's.

Without the velocity reducer: 396-400 fps.
With the yellow ring (smallest reduction): 363-367 fps which is roughly a 10% reduction.
With the white ring (largest reduction): 275-277 fps which is roughly a 30% reduction.

I didn't write down the values for the intermediate rings, but they seemed consistent within the ranges recorded.

As for accuracy. I could only test for approxmatly 30', but accuracy seemed relatively unaffected. With the range included, hop up performance also wasn't able to be well measured, but it did seem consistant. I did not have any rounds fly off in strange directions, or rise/dive suddenly which is usually the sign the hop up is being affected.

All in all, it was a great investment. Only slightly more expensive than the m90 spring I would need to play indoors (_300 fps where I live) but without having to take the gearbox apart everytime I want to change it.

This product does exactly as it describes, reduces the velocity of an airsoft electric rifle. This works on basically every gun with with a threaded flash hider (the list is at the bottom). The velocity reducer is suppose to reduce by 40-50%, although this is for a stock tokyo marui airsoft gun which are generally around 275-290 fps. So on a gun which has a bit more kick it reduces to lesser degree. To simplfy this I will give a list of pros and cons.
Pros:
Easy to install
Removes orange tip
Lowers the FPS of your gun without disrupting the shot
Has four interchangeable colored rings to reduce velocity (which can all be painted black as they are metal)
Case has a nice little slot to fit your old flash hider
Doesn't have to reduce velocity, can be used as just a flash-hider
Cons
Very easy to overtighten to the point of no return (I have permanently got the red one on which sadly is useless for a 400fps gun) I have tried to use an allen wrench, and other methods to remove, but they are hopeless.

Best Band For Each Gun:
300-325: Yellow (This should reduce it down by middle-range amount)
326-350: Red (Red should reduce it by a middle-range amount)
351-375: Blue or Red (Red should reduce it by a minimal amount while blue with reduce it by a noteable amount)
376-400: White or Blue (White should reduce it by a noteable amount, while blue will reduce it by a minimal amount.

Summary of Review:
I would say this item is the best thing to buy if you want a new flash-hider, because if you actually end up needing to reduce the guns velocity it is just a few steps away. Be carefull when tightening as it easily over tightens, with guns that are 400FPS use the blue or white rings as the red and yellow with make little difference.

Guns that support this product (This is from the box, these are all tokyo marui):
M4A1 & RIS
DR-16
M16 A2
CAR-15
MP5K PDW
MP5 A4 &A5
MP5 R.A.S
G36C
P90 & P90TR
STEYR AUG
AK47 & 47S
AK
M653
MP5 NAVY

These are do not work. Unless you're firing on semi-automatic and not firing very fast, they'll only reduce the velocity on the first shot, and even then they won't do it by much.

If you are looking at this to reduce your gun's velocity for a game, you're wasting your money. No field will allow this, because it only reduces the first shots velocity and it can be removed easily. This item is no substitute for a gun that shoots within limits of your field. Don't wast your money, either get a gun that shoots below your local velocity limits or put a weaker spring in your gun.