Unleashed Solid Stage 1 Kit for Nerf Elite Alpha Trooper This kit includes metal trigger catch, 2x double strength trigger catch springs, reinforcement plate, and 5+ kg mainspring (2.5kg stock). When installed, the Elite Alpha Trooper shoots 90fps muzzle velocity with up to 70ft range (parallel to ground) and up to 80ft range (30 degrees angled to ground). Mod at your own risk! Increasing the spring tension can break or damage stock internal components of your blaster. Blaster not included.