All Threads. These hollow threaded tube is available in 2 widths and various lengths. Our 10mm wide allthread is for use in a 10mm lampholder to adjust the height of the bulb holder. Plus we have a ½” (13mm) solid brass all-thread, suitable for use with our ½ inch entry lampholders to attach to a collar or half inch female entry. We also have metre long lengths available in steel 10mm only.