What some of us use is a simple Timex kitchen timer and get a piece of elastic strip from a garment store(about 2" wide),fold over and stitch ends so it fits your wrist or arm(slip over)attach the timer with two pieces,(loop/hook) of Velcro(adhesive on back)and attach it so timer will be attached to elastic. Easily removed this way too. These timers go for about $3-$5. Simple and works. Get the one that times down for different phases. Hope this helps.