APR T/S/D Computer with Density Altitude (Denalt) DAP-204 (Plastic)
Density Altitude Computer
First of all, a while back you could buy a cardboard version of a Den-Alt from the government for fifty cents - I believe it was from the Bureau of Engraving and Printing. Whereas too few students have any idea of the effects of density altitude, even at airports close to sea level, as an instructor I wanted to be able to show the students what the effects of density altitude are. The reason I chose the Den-Alt computer is that it is the only one I could find.