The ThermaSol Smart PDM is the power distribution module which functions as the brains of the ThermaTouch2 control. All external devices are connected to the ThermaTouch2 control via the Smart PDM. Dimensions: 9"W (22.9 cm) x 4"D (10.2 cm) x 7"H (17.8 cm) Designed, engineered and built in the U.S.A.