AllStar Performance Immersion Heaters, Immersion style heater preheats oil in wet sump oil pan or dry sump tanks to reduce overall warm up time and improve lubrication during initial start up. 5/8" diameter stainless steel sleeve inserts into pan or tank and secures with a welded on 1/2-14 NPT brass screw-in fitting. 120-volt operation. WARNING! Do not plug heater into electrical outlet without being installed in tank and submersed in liquid, element heats up quickly and damage will result.