All of our XS Collars typically fit an adult cat, its a chunkier look but we love it. 
Harness sizing for cats is the same as for dogs so you can select from all of our collars and harnesses including the matching accessories. You may find STEP IN STYLE harnesses are easier to put on your cat than classic style harnesses so we've listed the ranges with Step In Style Harnesses here. Of course bandanas, tuxedos and snoods can all fit cats too depending on their size. Our luxury polar fleece snugs and knitted sweaters also fit cats.
Measure your cat as you would for a dog.