+We also fly commercial altimeters in some projects. The cheapest off the
+shelf altimeter we've used and often recommend to beginners is the
+[Missile Works](http://www.missileworks.com/) RRC2-mini. At about $80, it
+gets the job done for simple barometric control of dual deployment. Note
+that while early versions had a firmware bug that we believe is at least
+partially responsible for Bdale's loss of his first L3 project, recent
+versions seem fine. For another $20, the
+[PerfectFlite](http://www.perfectflite.com/)
+[miniAlt/WD](http://www.perfectflite.com/catalog/MAWD.html)
+adds the ability to records the barometric flight altitude profile. Both
+of Bdale's L3 certs flew with one each of these two commercial altimeters,
+and we often use the MAWD as a backup for our
+[TeleMetrum](http://altusmetrum.org/TeleMetrum) units during test flights.
+
+The [BeeLine TX](http://www.bigredbee.com/BeeLine.htm) boards from Big Red
+Bee are radio tracking transmitters that just work. They require an
+[amateur radio](http://www.altusmetrum.org/Radio) license, but we think
+anyone flying big rockets can and should get one of those anyway!
+