From the Ironman Classic Collection. The Timex® IRONMAN® HRM + Activity Tracker is a watch born of necessity. Inspired by a renewed appreciation for health, wellness, and the great outdoors, this sporty 43mm timepiece is designed to help empower a better, healthier you. Featuring an easy-touch heart rate and daily activity monitor, the IRONMAN HRM + Activity Tracker is battery operated—no app, no charging, just function—and comes complete with a battery hatch on the case back for an easy swap when necessary. The brand has packed with all the practical features you’ve come to expect from the Timex IRONMAN including 50 meters of water resistance, INDIGLO® backlight; chronograph, alarm, and timer; and an impressively comfortable black resin strap.