Sera Reptil Thermo Comfort Mat Heating Mats For Reptiles, Amphibians And Invertebrates In Terrariums For Increasing The Bottom Or Back Wall Temperature In Terrariums Evenly Over A Large Area Easy Installation With Single Sided Adhesive Liner Incl. 4 Small Distance Pieces For The Corners Of The Terrarium, As To Prevent Stagnant Heat Available In Two Sizes: S: 28 X 28 Cm (11 X 11 In.) M: 28 X 42 Cm (11 X 16.5 In.)