The Bowflex Elliptical Wireless Heart Rate Chest Strap 8011909 is a durable and reliable accessory designed for gym and training activities. Made of plastic with a hard feature, this chest strap is specifically compatible with the Bowflex M3 MAX TRAINER, SINGLE BOX - 100942 model. Suitable for elliptical machines, this wireless heart rate chest strap is lightweight at 1lb and 8 inches wide, providing a comfortable fit during workouts. Perfect for tracking heart rate and enhancing fitness performance, this product is a convenient and essential addition to any home gym setup.