Defense Edge combines a durable machined aluminum exterior and a soft rubber lining to protect the edges of your apple watch from scratches and impacts. An easy snap-on design allows for quick installation. Defense Edge is compatible with all 40 mm apple watch collections and wristbands for series 4. Premium machined anodized aluminum exterior with a soft rubber lining; Metal does not touch your apple watch. Works with all 40mm apple watch (series 4) collections and wristbands and protects the edges of apple watch from scratches. X-Doria warranty covers defects both in materials and workmanship that result in failure during normal usage. Our warranty is valid when purchased from x-Doria only. The warranty period starts from the original date of purchase.