The FR31 features a 2" Bung Adapter (1/2" inlet), telescoping suction tube (extends from 22" to 40") and a swing return tube. This quart stroke pump can be calibrated with precision to allow accurate quart or liter measurement of oils and other non-corrosive petroleum products. The FR31 was constructed with a one-piece piston and heavy-duty cast iron housing as well as a smooth rack and pinion action all of which contributes to greater ease of use and increased durability.