A handy item for the restringing technician that gives a fast accurate and visual demonstration of bridge bearing to your customer.
Simply place the middle prong of the gauge on the string between the bridge pins. Align the end prongs over the same string and observe the amount of "rock" that occurs. If the gauge cannot be "rocked" on either side of the bridge, then a negative bearing situation is in effect and should be corrected.

Gauge is solid brass and measures 1-1/2" wide x 3-3/4" long.