Features: Modify Baton Flat Hopup Bucking Fits standard AEG hopups and barrels S-Nubs (Silicone-Nub) are made specifically for certain hopups. They just fit and require zero cutting. Moreover, you don't need to flatten the hop arm. This package works best with our R-Hop, perfect fit, No-Sanding, Available in our store. R-Hop is extremely effective at hopping BBs. So normal nubs are usually too thick for R-Hop, and will result in overhopping even if the hop-dial is at zero. Thus the thickness of S-Nub for Krytac Prowin and Madbull is 1.25mm. So you won't overhop at zero. The "sweet point" is around half at the hop-dial. S-Nub for VFC & Lonex is 0.8mm thick.