Review on Rechargeable Waterproof LED Dog Collar - 7 Color Change, Super Bright, High Visibility, 10H Working Time - Small Medium Large Dogs by Amanda Hall

Not adjustable, so measure your pet correctly. This is very bad for my service dog. Loose enough to twist but not come loose. She is a medium height but petite girl who needs the size we bought. I just solve the rotation problem by having them put it on with a different collar and make an X pattern out of it. My daughter loves it because her room has LED strips and she can make my dog match any color of her room. It's also easy to charge, but don't lose out on the included charging system. You definitely can't just use a phone charger when you have to.