Classic Army Metal Hopup Unit for Classic Army M4/M16 series. Also works well with all metal body upgrades from various manufacturers. Even works with stock Marui M4 and M16 style airsoft rifles with some modification.
Classic Army MP5 (P065M Type) Hopup Chamber for replacement or repair of existing hopup units. Can be used to replace any TM/Classic Army compatible MP5.*Note: Not compatible with new B&T eries MP5's from Classic Army.