HEATIT HISD 18-feet Pipe Heating Cable with Built-in Thermostat Use for water filled plastic (including PEX) or metal pipes. Not use for anything else, like empty water pipes, fuel lines, hoses, gutters, steam lines and so on. Two year limited quality warranty. If you are not completely satisfied with HEATIT heating cable, please don't hesitate to contact our customer service in any time, we'll try our best to solve your issues. Pre-assembled easy to install. Including grounded plug with light, built in thermostat, and instructions. Easy to install and use. 120 volt, 7 watts/ft. Built in thermostat to turn the cable 37F on 50F off. Only use 5 amps or less of electricity. Energy saving. 100% screen rate with the Aluminum foil and tinned copper braid. Both CSA and ETL approved. Industrial grade heat shrinkage tube for connection. Tough XLPE as inner insulation and weather resistant PVC (high-low temperature) as out jacket. Maximum 1/2 in fiberglass insulation was used over the heating cable for lower temperature protection. Pipes must be at least 3 feet and at least 3/8'' and less than 1 1/2'' in. diameter. No crossing. No spiral. No overlap itself. Only straight. Testing the cable before the installation. Uncoil the cable, plug in the heating cable and then put the thermostat part of the cable into an ice bucket for few minutes. When the temperature is below 37F, the thermostat will energize the cable to work. Normally you can feel the slight warm on the heating cable in few minutes. To avoid the overheat, please don't plug in the cable for a long time for testing. When you feel the slight warm, please turn it off.