The Airsoft Yellow Label Airsoft Man tests the 4UANTUM Friction Pro Hop-Up Bucking from 4UAD Smart Airsoft if gives some performance enhancement to the Tokyo Marui M4 MWS GBB Rifle. The Friction Pro hop-up bucking is designed for consistent, accurate shots by creating a centered spin axis and enough friction to lift even heavy BBs. Its unique design minimizes contact surface to ensure precision.