Match the heater to your vehicle's electrical system. Most cars, SUVs and passenger vehicles have one 12V battery and use the 12V/120W model. Most large/heavy trucks and lorries with two batteries use the 24V/200W model. If you're unsure, check your owner's manual or the cigarette-lighter fuse label before ordering. The two are not interchangeable — plugging the wrong voltage into a socket can blow the fuse or damage the heater and the socket.

No — please expect a compact, auxiliary warmer. At 120W/200W it provides a directed stream of warm air to help clear fog and thin/light frost and to take the chill off the driver's small area; it is not designed to heat the entire cabin or replace the vehicle's factory heating system. How fast glass clears depends on the outside temperature, the size of the windshield and how enclosed the vehicle is. Thick or hard ice should be removed with an ice scraper first.

It is intended to be used while the engine is running, which is also when the alternator is charging; please avoid running it for long periods with the engine off so the starter battery isn't drained. It draws power through the standard cigarette-lighter socket, so make sure that circuit's fuse can handle the rated power (120W on 12V / 200W on 24V) and that the socket is in good condition. No wiring or modification is required.

The outlet and body get hot in use: do not touch the front grille, cover the inlet/outlet with clothing or other objects, or place it near flammable materials. Keep both air openings clear, don't leave it running unattended, keep it away from children, and don't use it in wet or rainy conditions (it is not waterproof). Switch it off before unplugging, let it cool before storing, and keep it away from open flame and direct sunlight when stored.

It is built only for a matching DC cigarette-lighter socket in a vehicle — it is not a household heater and must not be plugged into wall/mains AC power. You can move it between vehicles only if they use the same voltage as the unit you bought; do not use a 12V heater in a 24V vehicle or a 24V heater in a 12V vehicle.