It consisted of an add-on 22 mm (0.87 in) stabilizer tube and fins that converted a hand-grenade into a rifle grenade.
The user then removed the grenade's safety pin and braced the rifle from a standing or kneeling position.
The chemical grenade was inserted into the short prongs on the base disc; a spring-loaded metal collar (called a "set-back band") slid over the middle kept the arming lever from releasing.
The user then removed the grenades safety pin and braced the rifle from a standing or kneeling position.
The shock of firing causes the collar to slide off in flight, releasing the lever and arming the grenade.