This is a Universal Handcuff Key!!! specifications for the size, shape, etc. of the blade of the key is taken from Deviant Ollam's Defcon talk on handcuffs, so thank you Deviant!!

when I printed my key, I used a replicator 2, with the high setting in makerware.

sacc

print at the high setting in makerware

break off support rods and smooth edges (I used a fine file and 220 sand paper)

BREAK OUT OF JAIL!!