Use different colours for each puppy and record their names on the reverse of the card. These collars are used to help identify and monitor the growth and development of your litter, and to avoid confusion over the ones who have found new homes. the card comes with a colour system on the back to help you keep a note of the puppies. These collars are easily adjustable with hook and loop fastening. Please note that these collars need checking daily to make sure they are not too tight. These collars measure 23cm long and 10mm in width. These collars are fully washable, please note only machine wash on a cool gentle wash or hand wash with minimum detergent.