Rocket Electronics

	Adrel Smallest altimeter available (fits BT-5 or less) for competition and record flights and FAI, sold by North Coast Rocketry (certified for contest and records)
	Altus Metrum Open hardware and software designs for high powered model rocketry, available from a variety of vendors.
	Perfect Flite Electronic altimeters and timers.
	Eggtimer Rocketry Inexpensive dual deployment altimeters and GPS trackers (in kit form).
	Featherweight Altimeters Home of the Raven altimeter
FlightSketch	FlightSketch Small Altimeter. Model rocket kits, motors and building supplies
	Jolly Logic Altimeters and a parachute release.
	MicroPeak Altimeter Very small recording altimeter. (available from Apogee) Apogee also sells Jolly Logic, Adrel, Missle Works, Perfect Flight and other altimeters and timers.
	Missile Works Corporation Altimeters and other rocketry electronics
	WMI Model Aeronautics Telemetry (tracking) based tracking transmitters and receivers