I purchased a couple of these right before moving to Phoenix. Never actually used and I doubt i'll ever need them down here, lol. I attached a few pics.
The package read:
little dog heated wellness cushion
Soothing heat & softness to keep your pet extra cozy.
*Designed for warmth and comfort for extended periods of time
*Safe, low voltage warmer
*Double insulated chew-resistant cord
*Two sided cover reverses to chocolate or sand
*Washable and dryer-friendly cover
*1 year limited warranty
It says for all pets up to 45lbs and measures 31.5" x 25.6"
Heated Wellness Cushion? - Little Dog - PetSafe Brand Official Website
Is this what you are looking for?