Size:20 Pack The TOGGLER SNAPTOGGLE BB toggle anchor provides a secure hold from within various hollow materials 3/8" to 3-5/8" thick including gypsum board, drywall, and concrete block, includes 1/4"-20 UNC bolts, and is made in USA. The anchor channel will not rotate when installing the bolt, whether installing by hand or with a screw gun, and will stay in place if the bolt is removed to facilitate fixture and screw changes. If using bolts other than those supplied, the anchor accepts 1/4"-20 UNC metal bolts with a minimum length equal to the thickness of the item being fastened and the thickness of the mounting material plus 1/2". The SNAPTOGGLE anchor meets Federal Specification FF-B-588-D for Type V anchors. The anchor consists of a corrosion-resistant zinc-plated steel anchor channel that inserts through a 1/2" drilled hole in walls, ceilings, or floors and installs against the back side of the mounting material; plastic straps attached to the channel that position it into place; and a plastic cap that slides down the straps and presses into the drilled hole firmly to lock the anchor channel in place behind the mounting material. Once the cap is set in place, the straps snap off by hand. The item being fastened affixes to the mounting material by inserting one of the included bolts through the item, into the drilled hole, and through the anchoring channel behind the material and tightening.