Universal Mounting Brackets: The updated design of the clamps allows for use with any light or accessory, by providing a flat mounting surface. Available in 9 sizes: 0.75in, 1.00in, 1.25in, 1.50in, 1.75in, 2.00in, 2.25in, 2.50 in and 3.00in. Clamps are sold as a pair (2), and feature a rubber insert which allows for additional adjustability in mounting diameter as well as protecting the finish of the tube you are mounting to. Larger size clamps feature a set screw to prevent the clamp from rotating around the tube. Clamp sizes 0.75inthrough 1.75infeature a through hole for M8 mounting hardware, while sizes 2.00inthrough 3.00inhave a M10 through hole. Mounting through holes can be drilled out or used with spacers to adjust size.