Windshield Wing Nut
A nice chrome plated wing nut (3/8-24 thread). On a Model A: Used on the open car All years 28-31 used them at the top where the windshield pivots. The 30-31 also uses them to attach the upper stanchion to the lower stanchion. Therfore a 1928-29 requires two and a 1930-31 requires four.
On a Model T used to lock the windshield in place on the stanchion. 1923-25 requires two, 1926-27 requires 4.