TOKYO MARUI REAL GAS BLOWBACK M4A1 MWS CUSTOM CHAMBER Stable HOP UP and great for long range! For keeping secure position of the hop tensioner! Designed for GBB M4 series! This custom chamber is compatible for Tokyo Marui Gas Blowback M4 series! The "elevating unit" on the HOP arm will keep secure position of the hop tensioner so the hop-up will be stable. Also, this item can be used with LayLax HOP Tensioner .So various setting is possible. ※Please note if the HOP UP is too strong, it will lead to bullet jamming and damage product. PRODUCTS CONTENT・Chamber Cover R・Chamber Cover L・Hop Arm・O Ring COMPATIBLE TYPE (Tokyo Marui Gas blowback M4 series):・M4A1MWS・CQBR・M4A1 CARBINE MATERIAL: Zinc diecast TO GET BEST RESULT, USE WITH FOLLOWING UPGRADE PARTS・Marui Wide Use Air Seal Bucking・HOP Tensioner ・TM GBB M4A1MWS Inner Barrel 250mm(Inner φ6.03mm)