What is a Key Gauge? - [Decode keys instantly] 

To determine the depths of a key, slide the key down the gauge until it stops. The numbers above the gauge will correspond with the correct depth for that space.
Every locksmith should have one of these in their tool arsenal. They come in handy for quick decoding.
This specific key gauge is good for very common keyways including: KW1 - SC1 - WK1 - WE1
This key gauge is called the KDO1 and can be bought through this link:
www.uhs-hardwa...