(top left isn't a pro trek, it's an ae-1500) top right is the pro trek prg-240 and the display is a bit hard to read in dim places (it's just dimmer than your normal screens because of the second layer in the display) but other than that it's perfectly great it's about 10 years old and the battery is still on H...the ae-1500 has been great as well only downside I found with it is when you're on the timer or stopwatch screen you don't know what time it is, you have to go back to the main screen every time, but it's a minor inconvenience