Puppy ID Collar Kits for Litters Whelping Breeding Now it’s easier than ever to identify puppies in large litters! Packs of eight color-coded Puppy ID Collars have removable number rings to increase your identification options. Order multiple packs and mix and match colors and numbers to track litters of nine puppies or more. Durable nylon collars have adjustable Velcro tabs for a secure fit. For use with puppies between five and nine weeks of age. Material: Nylon and velcro Size: Toy collars measure 1/4"W and adjust to fit necks from 5" to 8" Regular collars measure 1/2"W and adjust to fit necks from 6" to 12" Large collars measure 1/2"W and adjust to fit necks form 10" to 16" Each pack comes with: 1 Lime Green, 1 Blue, 1 Pink, 1 Light Blue, 1 Hunter Green, 1 Purple, 1 Red, and 1 Black *For litters of more than eight puppies, buy multiple packs and use the numbers to distinguish between collars of the same color.