Zoo Meds ReptiCare Rock Heaters Are Made Of A Hydrated Rock Material That Is Twice As Strong As Cement Or Pumice, Resulting In Excellent Conductivity And Increased Product Longevity. Hot Spots Are Not A Problem With A Completely Encapsulated Full Coverage Nichrome Heating Element That Distributes Heat Evenly. Zoo Meds Deluxe ReptiCare Rock Heater Features A Rheostat Control Allowing You The Ability To Adjust The Surface Temperature. Features A Rock Heaters Function Is To Facilitate Digestion A Rock Heater Should Never Be The Sole Source Of Heat Never Cover Or Bury The Rock Heater With Anything If Your Reptile Never Leaves The Rock Heater Then Your Terrarium Is Too Cold And You Need An Additional Heat Source (i.e. Ceramic Heat Emitter Or ReptiTherm UTH Heater) Zoo Med Rock Heaters Are CUL/CSA/T1/2V Approved Specifications Size: Mini Wattage: 5 W Warranty: 1 Year Certification: CUL/CSA/T1/2V Instruction Manual.pdf