Each pump head system is composed of a heavy-duty pump head, cartridges, and tubing¿each optimal preset tubing retention (order cartridges separately). They feature stainless steel rotors, Rulon rollers, and PSF ends. Occlusion is offset, tangential, and adjustable. For small cartridges, optimum retention is preset¿simply load tubing and start pumping. Recommended for use with small cartridge 07519-85 and microbore 2-stop tubing sizes.