Coupler Snap Pin 3/8" x 2 1/4" for Securing your Trailer Coupler

This is a Zinc Coated Snap Pin with a 3/8" diameter.  Although you could use it for securing anything with a 3/8" diameter hole, the most common use case on a trailer for this part is going to be locking the Coupler Latch in place, so that it doesn't come undone unexpectedly while towing.  The Square portion of the Snap Pin lifts up once you pull the end off of the pin, then you can insert the pin into your trailer coupler, and then close and latch the square portion over the pin again to keep it secured.