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 resin-hardener, 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.