Nine Ball Barrel 94.5mm/6.03mm Tightbore Hi-Capa 4.3 Inner bore width of 6.03mm with a ±0.01mm tolerance! The Nine Ball tight bore steel barrel for gas blowback handguns is the result of all the accumulated technologies and experience gathered from the Prometheus EG barrel series. The Nine Ball tight bore power barrel reduces the amount space around the BB to increase the overall air pressure behind the BB itself. Reducing as much possible air loss allows for the power barrel to achieve maximum performance. Compatible Model - Tokyo Marui Hi Capa 4.3 - Tokyo Marui USP Specifications - Barrel Length: 94.5mm - Inner Bore Diameter: 6.03mm - Material: Stainless Steel (SUS)