Dimensions: Small; 40x50cm, medium; 48x70cm, large; 58x88cm, extra-large; 115x72cm. Structure: With a five-layer structure designed to reflect your pets body heat. No : Doesn't require any - the heat-reflecting inlay does all the work! Waterproof: Ideal for if your furry friend has any little accidents. Colours: Choose from grey, coffee or blue colours. Pet pad: Get a winter pets self-heating pad! Material: Made using soft fleece with a non-slip bottom for safety. | Winter Pets Self-Heating Pad | Wowcher