Frank A. Edmunds 12-inch Adjustable Stretcher Bar Set,4012 12" Adjustable Stretcher Bar Set includes 4 routed Stretcher Bars and hardware; size 12 is for projects 12" x 12" or smaller These bars slide up, down and side to side, offering you many different size combinations They will adjust while your canvas is attached Holds your canvas tight, is easy to assemble, light weight and reusable Adjustable Stretcher Bar Sets are available in many sizes, select the bars that are equal to or greater than your canvass longest edge