Shadin MSRP is $4550 (seriously!).  Aircraft Spruce offers at $3573.

Think of it as a poor man's altitude preselector.  Instead of leveling your airplane at the designated altitude, it beeps to tell you to do it yourself!  Also beeps for DH or MDA and calculates Instantaneous Vertical Speed.  You'll wonder how you ever flew without one.

Simple to install: power, ground, altitude in (serial or grey code), and audio out.  Working perfectly right now; removing as part of upgrade.

Includes Shadin Installation Manual, Apollo Operation Manual, and instrument panel mounting bracket.