A very innovative Hop-Up rubber packing, designed for low stress and high performance.
-Featuring the zero inner hump.( no hump inside just plane rubber chamber packing )
-Enhance BB flight in long and straight path.
-Super hop up effect, very effective even with heavy gram BBs.
This hop up rubber designed to be paired with the Prometheus hop tensioner, great for all fps set up, especially, 400fps and above.