Sold as a 5 pack of stainless steel washers. 7/16 inch Outside Diameter (OD). 3/16 inch Inside Diameter (ID). Best used with 10-32 screws.

Commonly found on Wilderness Systems sit-on-top kayak with Slide Trax accessory tracks as well as Aquaterra-Perception kayaks with the the cast aluminum Chinook rudder bracket. washers (aka 3730-0105) 10-32-HDW