The description of RangeMaster Timer
RangeMaster Sports Timer is ideal for timing horse, track and athletic events. The app interfaces to one of these wireless electric-eye gates (sold separately):
RM-110, RM-501 and the RM-510
Use RM-110 for timing events that need only one gate such as horse barrel racing, cowboy mounted shooting and other agility events that start and finish at the same line.
Use RM-501 for timing events with separate start and end gates such as equestrian show jumping, horse racing, car racing, athletic running, football 5-10-5 drills, etc.
The RM-510 allows multiple gates and extends the range between gates up to 1,000 feet to time just about any sporting event, test and drill.