This is the same style duplicate key as you get in the box when you buy your handcuffs.
It's always good to have a few spare Handcuff keys around. Mr. S offers a number of 'specialties' keys that will fit most standard handcuffs. S&W... Peerless... Hiatt... Uzi.... Jay Pee, & American. Most of them also have the little 'nipple' on the opposite end to push in the 'double lock' button on your cuffs. The Longer length cuff keys make it also easier to hold onto them when opening the cuffs... esp. if you are trying to open them by yourself when they are behind your back. Get one of each as they are all cool to have. This one here is just a standard sized key for your cuffs. Sold as just One key.