Whenever you want to check your health, you can just use this heart rate sensor. It is easy to train without carrying phone or watch, you just need to use this heart rate sensor. It is made of nylon and spandex. The width of the product is 3cm, the thickness is 0.12cm. It is suitable for Polar, for Wahoo and for Garmin products. Item Name: Heart Rate Monitor Chest Strap Material: Nylon,Spandex Features: High Strength, Good Toughness, Wear Resistant Size Details: WxT: 3cm x 0.12cm/1.18" x 0.05" (Approx.) Expand Belt Length: 98cm/38.61" (Approx.) Two Hole Distance: 4.5cm/1.77" (Approx.) Notes: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: 1 x Heart Rate Monitor Chest Strap