40-mm Seafoam Sport Band — Regular Features: Made from a custom-developed high-performance fluoroelastomer, the Sport Band is durable and strong, yet surprisingly soft. The smooth, dense material drapes elegantly across your wrist and feels comfortable next to your skin. An innovative pin-and-tuck closure ensures a clean fit. Specifications: Case Size: 40 mm One Size - Band fits 130- to 200-millimetre wrists Material: Fluoroelastomer Compatibility with Apple Watch Models 38mm 40mm 41mm