B-Line Eaton series fastener hardware and accessories, Anchor is a two-part assembly consisting , Carbon steel ,3⁄16" x 4", Combo round head bolt is p

It is UL Listed. That matters if you are hanging boxes, strut, or conduit supports in a jurisdiction where the inspector wants listed anchors on the support path rather than generic hardware.

It comes complete. The ATB-18-400 is a two-part assembly: the spring-wing toggle plus a combo round head bolt, so you are not sourcing the screw separately. Combo head means you can drive it with either a Phillips or a slotted driver, which is handy overhead when you only have one bit on you.

A toggle is the right choice for hollow bases: drywall, hollow block, hollow tile, plaster over lath. The wings open behind the wall and spread the load over the back face, which is exactly what you cannot get from an expansion anchor in a thin hollow material. If you are anchoring into solid poured concrete, a toggle is the wrong part, use a concrete anchor instead. Also remember the wings need open cavity depth behind the wall, and once the bolt is removed the toggle drops into the cavity and is gone.

It is carbon steel, so treat it as an interior, dry-location fastener. Carbon steel will corrode in wet, damp, or corrosive environments unless it is protected, so for exterior or washdown areas specify a stainless anchor instead.

The 4 inch bolt length is the working budget. Add up the thickness of the item you are fastening plus the wall or ceiling material, and the remainder is what is left to get the toggle through and let it swing. With 4 inches you have plenty of room for standard drywall plus strut or a box, and you can stack a washer if the fixture hole is oversized. If the total stack-up gets close to 4 inches, step to a longer bolt.