A lot of people are using these improperly then leaving poor reviews for their lack of intelligence.These are specifically made for heating fluid on the other side of a metal container. Example: Oil Pans on vehicles. Any other use will probably result in failure of the product.People are saying this pad gets as hot as a 100w light bulb. Yes and no. Yes it gets as hot as one, but it actually gets HOTTER. A "light" bulb's intended purpose is to create light. The inefficient byproduct just so happens to be heat. This pads intended purpose is to create heat with no light, therefore all the 100 watts of energy is produced as heat. If improperly installed this pad will burn and self destruct. This is not a battery warmer, satellite dish warmer, or any other warmer except for a fluid encased in metal warmer. Plastic containers will surely melt. Metal with open air on the other side will cause the pad to get overheated and melt the nodes off, leaving you with 2 bare wires with 110 volts at the other end still alive until you unplug it.Think of it this way. Make a stew and leave the burner on all day. Once the liquid is cooked off, the pot gets hot and burns all the solid stew inside into char. Liquid is your insulator keeping everything from overheating and burning. Same thing with this pad. If properly installed on your oil pan, this pad will warm your oil and not overheat. Just follow the directions that clearly state this product is for oil pans. Degrease and clean your oil pan (you can remove it completely but I got under my truck and cleaned it). Sand the surface a little bit to provide more adhesion for the 3M adhesive pre-applied. Run the wiring from your bumper to the oil pan. Remove the plastic backing on the adhesive side of the pad and stick to your surface. Pretty simple. I have a 2000 Tahoe and 2003 Tahoe both 4WD 5.3L V8. The 4" x 5" was a perfect fit for the front of my oil pan. They are both brushed steel so it was already textured but I followed the directions anyways and slightly sanded it. If you have gloss paint, you get less adhesion to the surface area and it will probably not stick as well or last as long. It got down to single digits and I had no problem firing up my truck with it only on for 2 hours before starting. You won't get warm air blowing like an engine block warmer but engine block warmers don't keep the oil viscosity thin. Engine block heaters get you heat faster in the winter but still keep your cylinders and parts metal on metal until the oil gets around the engine. I'd rather have the components lubricated for less engine wear than a warm vehicle. Convenience vs Maintenance is your choice. My 2003 has both a block heater and this pad now since my wife drives that mainly with the kids (as well as being garage kept). My 2000 sits outside the garage and would have a hard time (dino oil non syntehetic) starting in single digits. Well, not hard time but took a few more turns to turn over to get started than usual. With this pad, it fires up with no struggle. The engine also warms a little faster since the oil is warm and warms up the block as it coats the parts. So you won't get warm air off the rip like a block heater, but you get warm air much faster than without it obviously.Just follow the directions. People using these on the underside of their battery compartments and crying they failed the next day are... special. The kind of people who don't read directions and who's final last words are usually, "Here, hold my beer" or "I can't see how this could go wrong!" Don't be those people. It's not hard to follow instructions. Your safety can depend on it sometimes. This device using electricity is one of those times.Pros:- Cheap- Easy adhesive-backed universal installation- Lightweight- Effective for my 8qt oil capacityCons:- Cord length may be a bit short to reach your transmission- Does not come with RTV or siliconeDetailed Review:I own 3 sets of these Kat's oil pan heaters. I am very particular about proper maintenance on my vehicles and care for them diligently. These oil pan heaters are overkill in my application, but provide me with cheap insurance and also piece of mind. I live in New York and drive 1 mile early each morning to the train station. Although the cars are all garaged, cold starts are still very hard on the cars. They also never get a chance to warm up especially when morning temperatures are below 20 degrees. Although I switch all my oils to 0w30 in the winter (the "0w" denotes the low temperature viscosity, the 30 is the operating temperature viscosity), one of my older cars still has a lot of piston slap (engine knocking noise). By pre-heating the oil with this pad, I've noticed faster cranking (when it is VERY cold) and I've eliminated the piston slap in cold temperatures with the side benefit of the heat coming on much sooner. I've recommended these to many of my friends already. They've also noticed the faster cranking and availability of heat, especially when their cars are parked outside.I currently have all 3 vehicles connected to timers that turn on 2 hours before before I need to leave the house. The timers are connected to the cars via light-up extension cords. I find the lights in the extension cords helpful in reminding myself and my wife to disconnect the cars before driving off.Regarding the minor cons (not significant enough to take away a star), I had recently considered using the same pad to warm the transmission, but found that the cord length was a bit too short to reach the front bumper. The solution would be to consolidate both the engine and transmission heater into a single extension cord, so this is not a big deal. The second note on the RTV/Silicone relates to the instructions to seal the edges of the pad with silicone to prolong the life of the adhesive. I would not imagine many people to have RTV or silicone readily handy. Including the small amount that the pad requires would have been nice. Although it can be a bit messy or annoying, I would definitely recommend sealing the edges to prevent water, oil and dirt from weakening the adhesive.Overall, this is a great buy, cheap, effective and easy to install!once glued on works greatI bought this to use as a satellite dish heater. I've only used it once and there was only about an inch of snow on the dish; not enough to impede the signal. I tried it anyway and it heated up quickly, and cleared the snow fast. I set it up on a smart light switch which controls the outlet it's plugged into. This outlet was already wired to a switch in my garage which I swapped out for the smart switch. Whenever the snow hits, I will just have to open the app on my phone and click a button or just ask Alexa to turn it on. You could also use an outdoor smart plug and do the same thing.I should have purchased a bigger one. On a 4 cylinder its a touch small in my opinion. But the battery was really cold too.This the 4th one I've purchased. I have one on my Honda Foreman and it works really well. Had one on this 4 cylinder and it got ripped off by ice.Block heater is the way to go but this does warm the oil.100 watt worked okay for 4 cyl engine it raises the oil temp about 50 degrees on cold nights. Sandpaper off the pan to bare metal and glue the edges good. I used shoe goo works fine. It does not heat up your engine but the warm oil pan is enough to make a difference in starting.I have these on all of our vehicles. They really do help. Our winter nightime temps are consistently sub zero. It isn’t unusual at all to see 20-30 below and even 40 below here and there. You put these on your oil pan and they get that oil circulating into the engine faster. They are pretty simple to install and stay put really well. Just remove your oil pan and clean it really well, go over it a little with some 120 grit sandpaper, and stick it on. Replace your oil pan and hang the plug through your front grill. You still need to let your car warm up before you take off, but it helps things along in extreme temps.