Flat Lock Nut.
Used to clamp the Tenax Button Part 31 to the material.
Part 33 is for medium thickness material.
Use part 302 for thin material or 33EL for thick material.
Brass nickel plated
"MADE IN ENGLAND"
It is highly recommended to purchase the Locking Key Part 34 to make installation easy.
Image above shows Part 302 attached to button.
Image above shows Part 33 attached to button.
Image above shows Part 33EL attached to button.