Designed for convenient and accurate metering of group size A, B, and C. As packaged, the pumps are ready to go into the Group Size B containers. A package of extension tubes for Group Size A containers is included with the set. Group Size C extension tubes are included in the 105-C Resin and in the 207-SC or 209-SC packages. Made of durable polypropylene, the pumps give years of dependable service. Read and follow the priming, ratio verification, and operating instructions that come with the pumps.