Triplex plunger pumps use three plungers, which reduces the pulsation of single reciprocating plunger pumps. The first apparatus consists of a closed container and a piston-like plunger. These consist of a cylinder with a reciprocating plunger. The trigger guard pivots down for stripping and detents in position through a spring-loaded plunger. The ends of the stop and plunger are often conical. The mine is stored with a pin restraining a detonating plunger. The connector consists of a barrel, a spring, and a plunger. The extractor retains the firing pin and is powered by its own plunger and spring. Usually the arm is fitted with a manipulating device resembling a sink plunger. Any further enclosed air is removed by gently pressing the plunger forward. Underneath was a pot of molten type metal and a plunger. Most often made of a rubber bathroom plunger without the stick. The movement of the plunger is measured using a calibrated scale. The model was produced with an option of rigid or plunger frames. The C11 frame was almost unchanged until 1951 when BSA added plunger rear suspension.