TestoKool 523 digital gauge set measures pressures and temperatures and calculates superheat/subcooling for up to 38 refrigerants on all AC/R, and heat-pump systems. Monitors and controls refrigerant with the integral two way manifold and sightglass. Records 1,000 tests and produces professional reports. The 523 includes an integral boot and stainless steel hanger. For more information, visit www.testo.com. —testo, Inc.