Fuzzbutt hammocks have a polar fleece lining, polar or cotton outer, and a hidden layer of cotton for more thickness. Available in two sizes 12.5×17″ or 20×15″. Choobs have a lining of polar fleece, a hidden INNER layer of polar fleece, and an outer layer of either polar fleece or fabric. Medium Choob measures 14" x 9" XL Platform Choob is made for larger cages at 25" x 9", you can also turn it over and hang it by the EXTRA side eyelets, and use it as a flat walkway or ramp. See the product comparison page for some helpful info. If hammocks or Choobs are out of stock, keep checking the “What’s being sewn?” page to see when new ones will be ready.