As accurate as strapped EKG sensing, Mio™ Alpha features electro-optical lights that sense your pulse and track your heart rate. No more hassling with chest straps with this strapless monitor that features heart rate zones with visual and audible alerts, timer, clock, data review, and simple two-button functionality. Monitor is rechargable by a magnetic USB dock, eliminating batteries all together! Soft, comfortable silicone strap. Packs include monitors, 10-port USB hub, and a hard plastic case with custom foam interior.