THIS SWITCH IS COMPARABLE TO A FURNAS , SQUARE D, AND MANY MORE. THIS SWITCH HAS AN UNLOADER AND A ON/OFF SWITCH. WILL WORK ON BOTH 2 STAGE AND SINGLE STAGE COMPRESSORS. IF YOUR COMPRESSOR DOES NOT NEED THE UNLOADER YOU DO NOT HAVE TO HOOK IT UP. 
1.Pressure Range:20-175PSI 
2.Connection:a manifold on the bottom of the switch,which is ONE-PORT or FOUR-PORT with Female or Male 1/4″（NPT、BSP）
3.Preset pressure settings:20-40PSI;30-50PSI;40-60PSI;50-80PSI;70-100PSI;80-115PSI;85-115PSI;90-140psi;95-125PSI; 110-140PSI;115-150PSI;135-175PSI. (Optional and Adjustable)
4.There is an adjustment instruction inside cover of switch.
5.Electric Ratings:Max 25 Amps.