Hoist rings are load-centering eyebolts. They are designed to be rigged from the center or the side and may pivot or swivel. Some hoist rings connect directly to webbing, chain, or shackles. Others have a hook-end rather than a standard bail, eye, or ring. There are three basic types of hoist rings: center-pull hoist rings, side-pull hoist rings, and screw-mount lifting rings. Center-pull hoist rings are designed to be rigged from the center and should not be set up to be pulled from the side. Side-pull hoist rings are designed to be rigged from the side and should not be set up to be pulled from the center. Screw-mount lifting rings are hoist rings with a fixed base. They have mounting holes for screws. In terms of movement, pivoting hoist rings have an eye that is designed to pivot 180°. Swiveling hoist rings are designed to swivel 360°. Product specifications for hoist rings include maximum load capacity, threaded length, overall bail length, overall bail width, bail radius, bail thickness, and weight. The bail size is defined as the bail diameter for round-eye hoist rings, and the bail width for oval or triangular hoist rings.