Master Lock's all-new Push to Lock Receiver Lock allows the user to hear and feel the locking mechanism engaging when securing trailers to nearly any hitch, fitting 1/2- or 5/8-inch receiver holes. The lock features a swivel-head design for easy installation in tight spaces, locking heads made stainless steel to resist corrosion, key-retaining function to prevent false locking, and color-coded barbell style to signify differences for marine or heavy-duty applications.