3/8" Flush plugs used in plugging 3/8" holes in sheet metal. these plugs Manufactured by caplugs are some of the nicest in the industry. these plugs are called flush because they plug the hole and have a slight dome to them making them look smooth and giving the plugged hole a finished look. If the hole is slightly larger than 3/8" or .275 thousandths I recommend using 3M auto body sealant to glue the plug in so it will not fall out.