I have used itac2-regular strength before, and it works really good, if u know how to use it!
My advice is that you need to get a small amount with the back of your fingers (ex. middle knuckle) in order to get some to the parts of your body you want to get a very good grip. Do not get it on your palms, it wont work it just gets sticky, use another product for hand grip.. It only works for the rest of your body. That is how it works on my skin anyway! Really good for super advanced moves where u mostly grip with the back of the knee, legs and feet.
The amount contained in this jar is enough, it looks small but theres a lot there because you need a small amount every time you apply it anyway.. sooo enjoy!! :)