Total rubbish! And of course, the first time I used it to find out about it was when the returns window closed. Used to check tires. Said he pumped them all up to 44psi. I was driving home from work last night and my tire pressure light came on. I used my husband's tire pump to check and all of my tires were in the 28-30 range. This is nonsense and doesn't work. And that's for super hot. The label says don't use it for more than 10 minutes because it gets very hot and they weren't lying, but it's closer to 2 minutes otherwise using this thing could burn your flesh.