This self-heating bed is the ideal choice to keep your pet warm on those cold winter nights, We just wish they made a bed version for humans. It contains a foam layer, backed with reflective foil, which is sandwiched between quilted polyester fibres and the bed's main fill, this reflects body heat back to your pet, keeping them warm. The quilted polyester lies beneath a super soft fleece cover, this layer holds warm air around your pet, providing added insulation. Particularly suitable for pets who suffer from arthritis, young and ill pets or those who just enjoy the warmth provided. Machine washable and non-slip base. Small size is 50 x 40cm, medium 60 x 50cm, large 75 x 60cm and xlarge 90 x 70cm.