Try Wallmart in the sports fitness section. I have
bought them there before. What I have found is that most any brand of
watch will work with most any of the HRM units. Usually they come with
the chest type HRM unit and you can add elastic straps to that to make it
longer and then use it on your horse when in camp or anytime you just want to
monitor their heart rate while they are in camp or at home. I have also
picked watches up at Walgreens. Watches do everything from stop watches
to alarm clocks to whatever and have nite lights. The price is a whole
lot cheaper than most anywhere else usually under $40 for both the watch and the
HRM unit. This has worked great for us.