R-Hop is the single most important part in airsoft that extends your effective range to over 60m/200ft. Max range of 90m/300ft can be achieved (with M130 spring, 1.7J). Perfectly Fits Lambda "One" Precision Stainless Steel 6.01mm Tight Bore Inner Barrel for Tokyo Marui Spec AEGs. NO SANDING is required. This R-Hop is Extremely hard to fabricate due to the 2 X 94 degrees cuts. We are the only aliens on this planet who can fabricate it accurately, repeatedly. Traditional R-Hops are 1.5mm thick and airsoft barrels are 1.25mm thick. Thus, sanding is required. Our R-Hops are Exactly 1.25mm thick. Therefore, sanding is Not required. Made of Premium-Grade Silicone Rubber, to produce MAX spin. Cold weather resistant. Proudly Made in USA.