Locking Pins with a quick release ball at the end. 5mm pins will sometimes fit 3/16" recievers, and will loosely fit 1/4" recievers - It is recommended that you use a part that specifically fits your...
This 10 pack of 1/4" x 1" stainless clevis pins comes with stainless split rings. These pins are used with the Zim C420 and on a number of small sailboats.