Ph D Fitness Overview The RS300X SD Comes with Polar RS300X training computer, Wear Link+ transmitter, S1 footpod, RS300X Getting Started Guide, & S1 foot pod user manual. Specifically designed for runners who wish to monitor their heart rate, speed & distance. The S1 Foot Pod is lightweight & attaches to your laces. Everything you need to monitor & improve your running performance can be found here. To ensure accurate results, the watch will request your weight, height, age, gender, & maximum heart rate.