Durapet Bowls are made of high quality, heavy-duty stainless steel with a permanently molded rubber ring in the base that prevents sliding and undesirable noise. They are dishwasher safe and the rubber ring will not come off. Unlike plastic bowls that may harbor bacteria or leach toxic plasticizers and colorants when they come in contact with food , Durapet Bowls are hygienic and will prove more economical in the long run when compared with plastic dishes. Durapet cat dishes are now available and feature a more narrow profile for toy dog breeds and cats.