Compatibility: Works with traditional or smart watches with a 20mm width universal flat interface. For example amazfit bip 3 pro smart watch, for more models, please continue to check the list in the description below 20mm Strap Size: Available strap lengths min 4.3" - max 8.1" (min 110mm - max 205mm). Taking the installation of amazfit bip 3 pro smart watch as an example (watch length 1.69 inches), the ordinary strap fits a wrist of 6 inches - 9.8 inches (155mm - 250mm) Material: stainless steel metal mesh belt and magnetic buckle Modern Milanese band: the magnetic clasp is easy to move and adjust the strap size to your wrist Easy to use: Quick release pin strap is easy to install or remove