Prisma 200: ABS plastic case, Large, easy to read LCD display, Stopwatch function, Normal time display, Selectable time resolution 999 mins., 59 secs. or 9 hrs., 59 mins., 59 secs., 1/10 sec., Loud audible alarm, 2 channels with start / stop operation, either separately or together.

Prisma 400: Generally as Prisma 200, but additionally with: Sequence programming, function window, 4 channels

Both models: Temperature range: -10 °C to 55 ºC (in use), -20 ºC to 60 °C (in storage), Battery Type: AA (R6)