8200 Waterproof Programmable Interval Timer Stopwatch | Timers for Kitchen, HIIT, Running, Sports and Outdoor Exercise | Countdown up to 100 Hours | LED Digital Clock for Workout

Works well. Easy to use. Great value.

The interval beep stopped sounding every time. It slowly got worse and worse and now just doesn’t work. Past the return window now. Would not buy again

Needs to be a little bigger for the 'hold' while teaching, the instructions are overly complicated and not well written & the buttons need to be more responsive.

It does what it's supposed to. It seems a little smaller than a GymBoss, which, for me, is a good thing. Being rechargeable, instead of a AAA battery is no big deal in itself, but it probably makes it sealed better, more truly waterproof. The biggest difference for me is the lack of an available wrist-strap, which I do have for my GymBoss. Got a wriststrap for me, Honmax?