Handcuff Key Standard. The Handcuff Key Standard is universal fit for law enforcement Handcuff Key Standard and is nickel plated and has the double locking pin on the end. Handcuff Key Standard Great for law enforcement, security, and police. Handcuff Key Standard measures 1 7/8" long X 5/8" at the rounded area 1/8" thick Handcuff Key Standard. Handcuff key is new item.