OEM JZA80 / MKIV Supra Front Badge Spring Lock Washer - 90183-04046.
These spring lock washers are found on every original installed badge, you will find 90% of replaced badges no one uses they but Toyota with their engineering team would have used them for a reason.
Note: These don't come in original Toyota packaging as they aren't sold individually. This listing is for only a pair to suit the front badge.