No Drilling of Holes Needed Universal Design For Glass Thickness: 1/8", 5/32", 3/16", and 1/4" Frameless Sliding Shower Door Towel Bar Kit has a universal design which does not require screw holes in glass. The extruded aluminum towel bar designed to be used with frameless sliding shower and tub enclosure doors.Available in eight colors. Finish: Chrome Length: 24 in Installation Notes: The included (black) rubber gasket is ONLY for use with 1/8" glass; place the rubber gasket over the edge of the glass on the desired area and apply the bracket over the gasket (this may require gentle tapping with a rubber mallet). For all other glass thicknesses: if the bracket does not fit over the gasket, or is too tight with the gasket, clear silicone (such as Part No. 99AS-GLAM) can be used to secure the bracket to the door.