The hair pin is a silver, metal pin used to secure and lock parts in place. If broken, the part being secured will come loose and the pin should be replaced. This is an OEM part directly from the manufacturer. Most customers rated the replacement of the hair pin as an easy repair.
The swivel attaches to the rear wing with the hair pin. It is made out of metal and is sold individually. This is a Snapper and Simplicity replacement part directly sourced from the manufacturer for use in rear engine riders and yard cruisers. A set of pliers might be required during the replacement of this part. It may become broken and will need to be replaced.