The PSMR1 combines two meters with three functions. It includes a 3-phase sequence indicator with a motor rotation tester. Prevent damage to equipment by using the PSMR1 to check supply line phase orientation for devices such as scroll compressors or motors prior to installation. Bright indicators will alert you to open phases, and indicate the sequence of the connected lines. The motor rotation indicator will provide information about the direction the motor will turn based on the communications made to the three phase supply. Three year limited warranty.