Lifekey Coyote Smart Strap. Lifekey Smart Straps can be both bold and subtle. It's a sleek, comfortable accessory, while at the same time, a quiet companion that lets you focus on the task at hand. Lifekey holds important data and connects you with friends and family with just a tap. Every Smart Straps is waterproof, comfortable, and durable enough for every adventure in any condition. The best part? Smart Straps don't require batteries or charging to work. Store and provide secure access to important info including medical data like blood type, allergies, medical conditions and other relevant data. Tap with your smartphone to let family or friends know when you start/stop an activity like walking, running, sports and more. Device and data are encrypted and can only be accessed by direct "tap" from a smartphone. Designed to be HIPAA compliant. Contacts are notified whenever data on the device is accessed. Water Resistant. No batteries or charging. No subscription required. Compatible with smartphones running Android and iOS 11 or newer. Imported.Sizes:S: 5.9" M: 6.3" L: 7.8"