Here it is, two great ideas in one place. The Flash, and the LED collar. Be seen out there, be safe out there.
To properly fit the Flash harness, measure the dog's neck circumference half way between the usual collar position and shoulder blades. Not sure about size? Go by the weight of your dog!
•S 18.5-19 inches (40 - 49 lbs.)
•M 19.5-20 inches (50 - 59 lbs.)
•L 20.5-21 inches (60 - 69 lbs.)
•XL 21.5-22 inches (70 - 79 lbs.)
•XXL 22.5-23 inches (80 - 89 lbs.)
Collar Neck Size:16 - 22 inches