I dont rember what size it is i only used one pice of split loom to do a ide ribbon that runs from my sound card to the audigy sound front if i had to guess its 1/4 or so. The spiral wrap is from compusa and it comes in two sizes 7/16 & 9/16 and comes with all the cable ties and and wire mounts same way with the expandable sleeving the links below are some ideas you can find them cheaper just looking up some references to give ya a idea and i gotta go to work