This West System 303 (3:1 ratio) Positive Displacement Pump dispenses three parts resin and one part hardener (3:1) by volume. It consists of two separate parallel pump systems, one for the resin and one for the hardener. The two systems are operated simultaneously by a single lever. The pump delivers 2.3 fl oz of resin and hardener per full stroke of the dispensing lever. The reservoirs hold two gallons of resin and one gallon of hardener. For use with 105 Epoxy Resin and 207 Special Clear Hardener or 209 Extra Slow Hardener.