Glowdoggie Leuchtie LED Safety Collar, Blue Classic, Size 21" Made in Germany. Built to last. Superior quality and performance. 100% Waterproof. 100 hours of shine time with 2x AAAs. Does not flash/blink as only cheap collars do. 2 year warranty. Ongoing customer support and repairs. Free shipping. Delivery within 3-5 business days after order. Size relates to your dog's head circumference. Please see sizing details below. A dedicated safety device, cannot be attached to a leash.