These are priced at just enough to cover mail service at $.05 ea. They are offered in packs of 10 These awesome Aquarium Animal ID cards are 2"H x 3"L These are made out of window cling film and can be written on with an ultra fine tip Sharpie, or a good ball point pen. They are super easy to place and remove and do not leave any residue. They can be used on glass cages and tops, as well as plastic tubs! If you have any trouble getting them to stick, just rub the back of the film on your shirt like a balloon to build a static charge.... cleaning and rubbing the glass surface also helps. Once they stick, they will not fall off. Hobbyists will find these super handy to keep track of important ID, Tracking, and Breeding information. Stores and Distributors will find them handy to Identify, Inventory, and Price specimens for sale. These are available in Fish, and Animal Versions.