• Slightly narrow entrance for better sealing to achieve more consistent power output.
• Special pressure point geometry greatly improves hop up performance and more predictable trajectory.
• Suitable for WE Open-Chamber System GBB Rifles

NOTE: Due to special pressure point geometry, this product is optimized for use with inner barrels with open type hop up slot.

i.e. Marui original VSR inner barrel and most compatible barrels with similar opening; Some inner barrel may have compatibility issues e.g. RA-Tech WE GBB Barrels, Tanio-Koba VSR Barrels