With the WaterRower Starter Kit you get even more from your Waterrower. Use the heart rate belt to measure your heart rate during rowing. The protective mat is supplied so that you protect your floor against scratches and bumps. To keep your WaterRower in good condition, use the included maintenance kit to keep your rowing machine as good as new.Note: the heart rate belt can only be used with the S4 monitor. This means that it is not compatible with the WaterRower A1 Home.