Like Paul Revere's midnight ride, the Garmin HRM-Tri/HRM-Swim Accessory Bundle will go down in history, if for slightly different reasons. Serious triathletes will be sure to light a candle or two in celebration, because the bundle's two heart rate monitors fill all the gaps in a serious training plan. The HRM-Tri, made from a soft and stretchy material, is ideal for land-based activities and open-water swims in wetsuits, and boasts up to 10 months of battery life at an average training time of 1 hour per day. The HRM-Swim, on the other hand, is tailor-made for swimming pool laps. It features a wide, chemical-resistant, and non-slip strap to hold up to the rigors of indoor laps and the pressures of flip turns. If you swim three hours per week, the easily-replaceable battery will last up to 18 months. Both heart rate monitors can easily transmit data to Garmin Epix, Fenix 3, or Forerunner 920XT devices, too, so you can analyze all your data at your leisure.