- 60 Degrees Rubber Made - Suitable for Marui / WE / KJ GBB Pistols, WE GBBRs and VSR-10 compatible Air Cocking Rifles - The properties of the rubber are highly elastic and anti wear. - 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. - C-Clip to Enhance Lip Stiffness for Further Sealing