300 Mini Pumps are designed for convenient and accurate metering of Group A, B, and C sizes of the WEST SYSTEM® 105 System. The 300 Mini Pump Set Contains one resin pump and two hardener pumps. Pumps mount directly on the resin and hardener containers and eliminate the mess involved with measuring by weight or volume. Calibrated to deliver the proper working ratio with one full pump stroke of resin for each one full pump stroke of hardener for 105/205-206 the pumps deliver approximately 0.8 fl oz of resin/hardener with one full stroke of each pump. For 105/207-209 pumps deliver approximately 0.9 fl oz of resin/hardener with one full stroke of each pump.