The CNC 7075 Aluminum Blowback Unit is machined with precise CNC tolerances from 7075 Aluminum for improvements in stability, durability and overall performance. It is designed with a plastic inside to reduce wear on the nozzle. And there is a plastic insert with the appropriate angle so the hammer never gets caught in the BBU. Optimized weight only 14.38 grams. Adjustable BBU for turning standard BBU to early air cut off BBU. The nozzle head is made of plastic to avoid damaging the internal parts of the hopup. It is machined with precision makes the nozzle move smoother, higher air tightness. Included: 1 x CNC 7075 Aluminum Blowback Unit 1 x CNC Aluminum Nozzle Usage: Use for TM Hi-CAPA 4.3 / 5.1 / Gold Match