What It Says On The Box:
The heat mats have two advantages for the animals; first they heat objects, e.g. stones and create warm spots for the animals to heat up and second they heat the animals directly. The infrared radiation of the heat mat penetrates the skin of the animals and creates a cosy warmth. Your animals will love to be in the effective range of your heat mat.
These heat mats create warm spots and allow to achieve heat gradients inside the terrarium.