This is a smart watch band. I bought it because the previous one broke, but the watch I have is an old model, and it's not returnable, so I'm selling it. I opened the outer bag, but the contents are new. Thank you. Black band compatible with SW308 model, adjustable from 145mm to 220mm. - Color: Black - Compatibility: SW308 model - Size Range: 145mm to 220mm (5.7 inch to 8.7 inch) Thank you for looking.