Compatibility：
Fit for Fitbit Alta / Fitbit Alta HR. The Fitbit device is not included.
Feature:
1. Made of quality silicone material, environmental and healthy.
2. Comfortable to wear. No problem for doing in most sports.
3. Skin-friendly and provides comfortable feeling when you wear it during sleep.
4. The size can be adjusted according to the circumstance of individual.
Fit Size:
S(Small Size): 5.5" - 6.7"
L(Large Size): 6.7" - 8.1".
Packing Include:
1 x watch strap for Fitbit Charge 2 (band only, smart watch is not included).