PPS CNC Aluminum Shock Transfer System (STS) for M4 / M16 Series Airsoft AEG Rifles

"HEADS UP!!! DOES NOT fit with a PROWIN style hopup unit.

Other than that, its beautiful

"Fits a normal hop up. The only problem I encountered were the screws. Instant lost due to vibration of the gun the caused it to unscrew in less than a day of playing, but luckily i did not lose the pins. I poked around the website for a replacement screw and the WE PDW Airsoft GBB Rifle Part #47 - Stock Retaining Screw is the perfect replacement!! locktite the screw and I was good to go.

"Very solid and well built, but if you are running a dmr (like me :D) and have power and accuracy, you might need this, but small problem. I use a prowin hop up, it is too large to fit both the brace and the hop up, so as long as you have a standard hop up chamber. I plan to use this in a different gun instead. I imagine it would do its job just well.

"So I don't want to take away from the fact that this is a fantastic peice of equptiment, but it doesn't work with newer rotary style hop up units. If you have an older model hop up this'll be great in reducing the stress your V2 gearbox is taking. Though I feel It should be stated in the specifications what it's compatible with.