Unleashed Solid Final Stage Kit for Nerf Flipfury This kit includes plunger rod, slam fire catch, trigger catch, trigger, 7kg mainspring, white lithium grease, o-ring, trigger and trigger catch springs. When installed, the Flipfury shoots at 80-90 FPS (feet per second). Warning: Because the trigger included is metal, the slamfire function will not work reliably with the kit installed. Mod at your own risk! Increasing the spring tension can break or damage stock internal components of your blaster. Blaster not included.