Zak Tool #15P pocket handcuff key extension tool. 3 7/8" long with including key. "Enhances use of the original key due to the extended barrel length. This allows the user to manipulate the key by rolling the barrel between the thumb and forefinger. To replace the key, unscrew the end cap and insert a new key. Replace the cap and its ready for use. Original issue key is not included in the lifetime guarantee." Includes 2 keys.
I have several handcuff keys, but they are usually on my keychain in my pocket. I wanted a handcuff key I can quickly access and not have to fumble with keys. Moreover, if the key breaks, I can simply replace it!