THIS IS A DIGITAL PRODUCT FOR PERSONAL USE ONLY
These parts are designed to increase the efficiency of your Backdraft Phoenix HPA Engine when using short barrel lengths. They allow you to adjust the volume of air stored inside the engine. They can sometimes reduce the FPS of your airsoft rifle, but prevent over-voluming when the barrel is short.
THE SMALL SIZE REDUCER REPLACES THE BUFFER O-RING IN FRONT OF YOUR SPRING
THE MEDIUM AND LARGE SIZES STILL REQUIRE THE BUFFER O-RING IN FRONT OF YOUR SPRING
We do not have hard data on which volume reducer should be used with different barrel lengths since it will depend on your bb weight, desired fps, and barrel diameter. MOST BUILDS DO NOT REQUIRE ANY VOLUME REDUCERS.
Happy printing!