I followed the directions on theMax 200 website, which is I put a dowel in his mouth and marked how wide his mouth was right behind the canines. Then I called and gave them his height, weight and breed info. This is the second dog they have sent the perfect fit, the first time....
I have quite a collection from J and J ... Never did get a dumbbell that fit so well, I guessed and ordered and never returned ones that didn't fit. I've had three dogs, and order at least three dumbells for each dog, one for the show, one to train with and the emergency back up because I usually leave one somewhere!
Anyway thrilled that boy boys holding the dumbbell that fits right with no mouthing or rolling it around. Now to work on getting that perfect front with it in his mouth!