GFZ Gavinfuzzy SBL2-EX Hardware add-on Kit

Want to add a bit more ooomph to that GavinFuzzy SBL2? 

This is the SBL2-EX add-on kit, with some alternative parts to allow you some more plunger, more barrel, and pushes the FPS up to 275fps

This requires you to already own a SBL2 hardware kit, this is an accessory, not a complete hardware kit.