The Pocket Size Decoder Kit determines the original factory depths of most popular domestic pin and disc tumbler cylinder and automotive keys. It is ideally suited for giving the correct bottom pin size when re-keying new or worn cylinders. It is also an effective timesaver when used along with precision color pin assortments or when using original pins. Simply insert the correct information card into the top slot of the decoder. Lowering the depth pin into each cut, from bow to tip, will indicate the correct depths in the window at the top. The pivoting depth pin allows for easy decoding of Medeco angles. Each of the 2″ x 4″ (5 x 10cm) information cards also lists the manufacturers depth and space specifications.HKD-75 comes complete with a handy soft shell carrying case, 3 shims, and 111 information cards.