Abstract: A pump has a static piston (1) slidably received in a movable cylinder (2). The piston (1) is anchored to a body (4) and the cylinder (2) slides in the body (4). A displacement force applied to an end cap (9) of the cylinder (2) will displace the cylinder in one direction and a return spring (10) returns the cylinder in the opposite direction. A non-return valve assembly (11) enables material to be drawn into and pumped from portion (7) of the cylinder (2). A pin (5), passing through slots (6) in the cylinder (2), secures piston (1) to the body (4).