Shelf Keepers are designed to keep equipment on truck shelves while in transit. The "cam-buckle" releases easily to drop or remove the shelf keeper when access to the shelf is needed. Shelf Keepers can be used on trucks that are shelved out with metal supports or with 2x4 supports. The clear vinyl ID pocket will hold 3x5 card which can identify the items on the shelf. Pocket can be moved anywhere along the length of the Shelf Keeper. Shelf Keepers are made in two Heights 10" and 15" and for 4', 5', 6' and 8' long shelves. We will be happy to quote on custom sizes, please call customer service with your specifications. Shelf Keeper - ST perform the same functions but are made of a heavy duty netting so that the content of the shelf can be seen.