PG9 Black Nylon Waterproof Strain Relief, Cord Grip, Cable Gland 4-8mm 10pcs (PCGPG09B) This device is designed to attach and secure cables to control boxes, distribution panels, electrical appliances, machines, etc. This product is also used for sealing cables passing through bulkheads or gland plates. Cable glands may be used on all types of electrical power, control, instrumental data and telecommunications cables. Ratchet type lock nut ensures a firm grip on the cable. Nylon locknut included