ROBART Control Surface Deflection Meter

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

FEATURES:
A crucial 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 is in 1/16th increments, with 1/4,1/2,3/4 & 1" marked.
Fits large and little scale design airplane.
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No more errors with rulers and scales.
Quick and easy surface area adjustments.
Allows for precise differential adjustments.
Instructions are provided.

INCLUDES:
One SDI Gauge

NEEDS:
Constructed and Decorated Aircraft
Radio
Tape
Straight Pin