Heininger 6041 HitchMate 2" Stainless Steel Receiver Hitch Lock Pin diameter: 5/8 inch, Inside width: 2-5/8 inch, and Overall length: 6 inch Stainless steel gives your hitch lock more durability and a longer life Fits 2 inch x 2 inch trailer hitches (Class III and Class IV) Covered key slot prevents corrosion Made in USA