The insulating plastic material is . Not only speed can be adjusted, but also heat and brightness can be adjusted, and even closed. The governor can be inserted into two plugs, and can be connected with the blanket. It is widely used in fans, electric blankets, electric soldering iron, electric glue , small motor, white woven lamp, blower and so on. Product type: fan governor Power: 20-390W Voltage: 220V Frequency: 50HZ Note: When this product is used with a fan plugged in, the fan have a large current noise when adjusted to a low speed (this type of external speed control product is normal in the current market and not affect the use). If you cannot accept this current noise, please be careful when purchasing! Warning: 1. It cannot be used for equipment with a power of more than 39DW. 2. It cannot be used for dimming of LED energy-saving lamps. Plug Type: US Plug, it applies to Canada, India, Mexico, Thailand, Taiwan, the , the Philippines and so on. Colour:Black Material:plastic Package Contents: 1 x 220V Speed Control Switch 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.