If you love the latest tech you"re probably wearing a Fitbit Flex - Large on your wrist. Tuff-Luv are offering a range of removable / swappable straps made from silicone. This white strap is moulded to fit your Fitbit Flex - Large perfectly and includes a buckle to ensure the strap stays secure, no matter what sports and activities you get up to. Size Small: 140mm - 177mm (5.4" - 6.9") Size Large: 161mm - 210mm (6.3" - 8.3")