Zinc-plated Coarse Thread J Bolt with nut

J-bolts are a type of hook anchor fastener that are typically embedded into concrete foundations on construction sites. The top of the bolt is threaded so it can accept other threaded fasteners, and the bottom is hooked in a "J" shape to anchor onto rebar or other structural components in the concrete.
When installed, the hooked end of the bolt is submerged and cast in place while the threaded end protrudes above the concrete. Once the concrete has set, walls or other fixtures can be secured to the concrete base by threading a nut and washer onto the exposed bolt.