Startechcom cable management assessories startechcom cmhook1un the cmhook1un vertical cable management d ring from startechcom enables you to add a 1u metal cable hook to your server rack or cabinet to provide an organised channel for your cables made from high quality steel the cable d ring measures 45 x 100mm and offers a flexible opening for easy insertion of bundled cables providing strain relief for attached cables multiple cable rings can be attached to your rack where you need t