West System 300 Mini Pump Set Designed to be a convenient and accurate way of metering West System 105 Resin Epoxy. The Set contains one resin pump and two hardener pumps that directly mount onto the containers of the resinhardener, eliminating the mess from measuring by weight or volume. The 300 Mini Pumps are designed to deliver a proper working ratio. One full pump stroke of resin for each one full pump stroke of hardener. Made of durable polypropylene, with proper care these pumps can last.