Features and Benefits:

• The 3777 features 3" to 16" and measures the wear dimension of the brake drum
• The 3774 features 0 to 6" and measures wear dimension of the brake rotors
• Resolution / repeatability .0005" X 0.01mm
• Easy to read digital display
• Brake rotor gauge and brake drum gauge in one case

This two-piece digital brake gauge includes KD's 3777 and the 3774.  These are very similar in many ways, the 3777 is preset at 1-1/2" depth with indicators for .5 and 1".  These tools both have manual power on and off, Metric/Inch system interchange at any position, Zero setting at any position, data output interface and comes in one storage case.  Which makes it great, you don't have to worry about two cases!