This superior silicon Hop-Up bucking designed for use with GBB / VSR replicas by Tokyo Marui, KJW and WE, comes in black and boasts a 70° hardness level. Crafted from top-quality silicon and weighing only 1 g, it is a perfect fit for M4 MWS ZET / VSR TM / GBB replicas. This exceptional product is manufactured by Maple Leaf.