This sturdy and well-made item holds a beverage can or water bottle or coffee cup or a bicycle bottle. Attaches to most anything by the clamp-on mechanism. The clamp can be turned 360 degrees and works on tubing from 3/4 inch to 1 1/4 inch.....round or square or oval tubing. Easy on and easy off. The bottle holder itself is 4" deep and 3 3/8 inch diameter. I personally used it on my bicycle handlebars for my coffee carafe which would not fit in the usual bottle bosses. You do you!