The Two-wire Thermal Actuator for EP Heating Manifold is a slow opening thermal actuator that mounts directly onto the EP Heating Manifold and connects to the Uponor Climate Control™ Zoning System C-55 Base Unit (A3601012). It provides individual loop flow control on a multi-zoned manifold. Uponor Two-Wire Thermal Actuator, 0.167 A, For Use With: Engineered Plastic Heating Manifold, 1.58 in W x 1.58 in D x 2.47 in H, Import