1. Made of metal, it is extremely easy to maintain and replace spare parts; 2. Equipped with high-end precision processing heating tube, the heating time is short 3. Insulation resistance: equal 10Mohm 4. Electric strength: 1500V/1min (normal) 5. Temperature control range: 40C-50C The working principle of the heater: low-level cold water enters, hot water from above, a heating pipe, a temperature control type:120V Colour:black Material:Metal type:1000W Package Contents: 1x Engine Block Heater Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.