Holy scariness, Birdman. Be on the lookout for toy replicas of the famous Alti-2 Altimaster MA2-30 altimeters. Alti-2 has found some on the market made by a Hong Kong company for use in airsoft games. (If that jargon sounded wrong, it’s because I have no idea what airsoft is, especially if people buy fake altimeters to play it.)
The real MA2-30 is more commonly found in military skydiving, but if you find a crazy cheap altimeter, MAKE SURE IT’S ACTUALLY AN ALTIMETER.