Cylinder chocks

We occasionally move oxygen cylinders for my wife's business. This usually involves laying them down in the bed of the pickup, generally when getting them refilled.

These should fit 250-300cu ft. cylinders, and they're designed so that the feet fit into the ridges in the bedliner that came with the truck (a used Ford Ranger). The holes are to allow a cord to be run between a pair of chocks, if desired, to keep them from sliding apart durning use.