The TT21 is a two part low power transponder system, which includes an integrated altitude encoder.This transponder's low power qualifies the unit as a Class 2 transponder. Class 2 transponders may be used on aircraft cruising slower than 175 knots, and operating below 15,000 feet, IFR or VFR.

The front panel controller is smaller than a standard instrument, and the remote transponder is not much bigger than a pack of cards. The TT21 can fit into the smallest of aircraft – and yet it is fully certified and compliant with all the transponder requirements.

• Low Weight - less than 500 grams!
• Minimal Panel Space
• Low Power Consumption
• 130 Watts Nominal Output
• Integrated Altitude Encoder
• Simple Installation
• Support for 1090ES ADS-B Out

The TT21 can be mounted in a standard 57 mm (2¼ inch) instrument hole, or where space is really tight, in a compact mounting just 42 mm high.

The TT21 is TSO approved for fitting to European and FAA registered aircraft.