don't worry about it.
"designed to interface with heart rate interactive exercise equipment in health clubs"
simply means that you can use it on most treadmills.
treadmills or stairmasters or other machines at the gym are "polar ready". that simply means that they can pick up on the signal from the connector and display it on the machine and thereby interactively work with your heart rate (say you programm the machine for a workout with a steady 130 bpm pulse)