Bought for my wife as she was using the eye pads that heat up in the microwave. These are 10x better as they hold a constant heat level without going from scorching hot to cold like the microwavable ones. The added bonus is the massage you get on your eyes, temples and surrounding areas. It seems to last for about 45 minutes before battery is low. Easy to keep charged on bedside/couch. This is a great gift for someone who suffers from headaches. When I use it I go into a trance of sorts, the music, the heat, the massage is calming just prior to bed.