1. anti-lost rope for children/the old. 2. double wrist, adjustable width for children and adult. 3. key lock function. you can lock the kid wrist with the key on the adult wrist. 4. built-in steel material for the rope, the rope is durable and not easy to be cut. 5. 360â°rotation, you can let your kids go ahead and never mind their losing. 6. comfortable, breathable and wrist. 7. reflective rope, it can be seen far away 20m in the evening.