Hi Belinda, I use a Braun ThermoScan, which is similar to the ones the GP uses. I've had it for 4 years and used it on both kids and it works amazing. Its very quick and thats important when you have a wriggly, irritable baby on your lap lol! Not sure how much they are as I got it given to me as a gift and it was one of the best gifts I got.