<li>PPS Enhanced Upgrade Kit for Well L96 MB01 MB04 MB05 Airsoft Bolt Action</li> <li>Includes metal spring guide and upgraded spring and CNC Piston</li> <li>CNC Machining Aluminum Pstion</li> <li>Power up to around 500-550fps | Item Weight (gram): 100 / 150g with package | Built Material: Aluminum