They call it "professional" lube because it's made for folks who are experienced enough to take a fist in the ass. And like it. 

Fist It Extra Thick Lube is great for anyone who wants to play longer, enjoy more glide and comfort, and especially for those who like to explore the boundaries of butt stuff (please only use appendages and anal sex toys created for this purpose when exploring). The water-based formula makes it compatible with latex condoms and all types of sex toys, plus, it's dermatologically tested so it's body safe so matter where on or in your body it ends up. It's also colorless, odorless, and tasteless so it won't ruin the mood.

Wash it off with sex toy cleaner for easy clean up!