It's time to get rid of the mystery around that jar or drawer full of keys - the IdentiKey Card Storage + ID System allows you to organize up to four keys in a compact, flat cartridge, easy for storing just about anywhere. The included d urable, colorful write-on tags make key identification simple. Simply write on the IdentiKey Tag with permanent ink, affix it to your key, and slide it safetly into one of the integrated key slots in the card. The card can be hung or snapped together with another IdentiKey card to store up to eight keys together in the space-saving system.