Size guide: XS: Fit for 16 weeks to 5 months of age or up to about 55 lb cat S: Fit for 55-11 lb cat M: Fit for 11-165 lb cat L: Fit for 165 lb and up cat Application Steps: 2correct size is importantTake one of the nail caps out and tryt on your cats claws without the glue to ensure a proper snug fit 2Trim cat claws to the same length with that of the nail caps If the nail cap is too large, you may trim the open end of the nail cap until it fits Note: Do not trim kittens claws before applying nail caps You will need a sufficient claw surface for the glue to adhere properly 3Fill each nail cap a little glue, only glue in a part of the nail (about 13, never fill to too full to prevent overflow of the adhesive), Wait the adhesive is half-dried in the nail cap (Please be careful and avoid dropping glue on your hands or your cats fur, if you do, remove it with use nail varnish remover or dispergator) 4grasp the claws of your cat, slightly push aside the fur around the nail and expose the nail Put the nail caps onto the claw and make sure they are completely wrapped Wait until the adhesive is dry and continue with the next nail 5Observe your cat at least 5min to make sure nail caps are secure, then you have completed, We suggest you to distract your cat or feed his or her favorite food immediately after applying all nail caps Notes: 1Most cats will like their new claws, but some cats will reject generally, after wearing for the first few times, they will get used to them and without any discomfort 2Different cats, different movement and location (such as cement, grass, floor, carpet) etc, different wear rate of the nail caps Some wearing 3-5 days may wear out Some can wear 1-2 months or even longer 3Addition, The cat nails have scalability, we recommend you leave a little gap out when stick the nails, that cat nails have activity space