For optimal fit: Measure PAW WIDTH (not the same as boot width) Petite 1 X-Small 1 Small 2 Med 2 Large 3 X-Large 4 wide. Mark width of paw on paper and match to boot as above. The Durable sole is pliable super grippy and ideal to prevent slipping on floors and light duty outdoors - plus they stay on your dog s paws! Packaged four boots to a set in red or black in six sizes. Wide opening split seam top - making it easy to put on the boots. Two Velcro straps with slides fasten the boots in place. Generous foam pads at the closures create a secure grip and cushions the dog s paw when the boot is tightened. Durable boots are the BEST protection for senior dogs or ones with hip conditions that are having trouble slipping on hardwood or tile floors. (Limited breathability; for extended periods of time in boots use Ultra Paws Traction fleece dog boots). Tough water resistant polyester material with the top of the toe and sole wrapped in a grippy flexible skid resistant durable PVC or TPU (o