Also known as lag shields, these anchors are designed to be used with large diameter wood screws. They reinforce the hole and resist stripping. Each diameter is available in two lengths. The shorter length reduces drilling time: the longer length provides more strength. To install, tap into a drilled hole with a hammer and position your fixture.Then, insert a lag screw and tighten. Install flush or slightly below the surface. Pull-out strength and shear strength values are 25% of the ultimate values.