If you have ever worked in the yard and suffered muscle pain, I suggest you become familiar with my two best yard buddies. Yep, after pulling weeds, blowing box wood trimmings, and hauling off the said box wood trimmings, I became really familiar with the above. The Activ On rolls on so you can keep your hands from getting messy but it does not smell as pleasant as the Joint Flex. The Joint Flex is a cream and after you put it on what HURTS you have to wash your hands dozen of times to rid them of the smell. I have thought quit often that I would use a kitchen spatula to spread it on the hurting area. Then that utensil would be forever a Joint Flex spreader. The Kitty Justice is if you LIKE to hurt then DO NOT USE EITHER ITEM SHOWN.