3/8 in (0.95 cm). 3/8 in x 8-12 in (0.95 cm x 20-30 cm). For cats 6 lbs+ (2.7 kg+). Break away buckle! This collar is designed with your cat's safety in mind. Our breakaway buckle releases when it becomes entangled in bushes, fences, trees, etc. Included is a removable bell to help protect the local bird population. www.aspenpet.com. Made in China.