Nite Ize Nite Dawg Light Up Dog Collar Strong metal D-ring and quick release buckle. Glow and flash modes Visible up to 1000 ft. 1x replaceable 2032 battery included. Battery run time: Glow: 75 hours | Flash: 100 hours No reflective striping on XS size Measurement guide - Measure your dogs neck and add two fingers between your tape measure and your dogs neck.Fits:10"-13"(Inches) HIGH VISIBILITY collar with bright red LED; youll never wonder where Rover has wandered off to this time.