ROBART Control Surface Deflection Meter

This Is An SDI Gauge (Surface Deflection Indication) from Robart.

FEATURES:
An essential tool utilized to measure the amount of up and down or left
    and right on your design airplane elevator, ailerons, flaps, and
    rudder.
Precise measurement of surface area deflection in INCHES.
Measurement remains in 1/16th increments, with 1/4,1/2,3/4 & 1" marked.
Fits big and little scale design airplane.
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No more mistakes with rulers and scales.
Quick and simple surface area adjustments.
Allows for precise differential adjustments.
Instructions are provided.

INCLUDES:
One SDI Gauge

NEEDS:
Constructed and Decorated Airplane
Radio
Tape
Straight Pin