Designed to work in hydropneumatic (air to water) pressure systems where an excess amount of air needs to be released from the tank. Constructed of ABS plastic materials, Brady air releases are noncorrosive, nonconductive, and completely serviceable. The release features an extra large float with removable arm. Release mechanism consists of a buna-n rubber seal, polypropylene ball and 316 stainless steel spring. Factory set at approximately 20 P.S.I., fully adjustable from 0 to 40 P.S.I.