This is Great Planes' 5/16-24 Aluminum Safety Spinner Nut.

Features

Lightweight aluminum construction.
Satisfies AMA's safety requirement for spinners.
Comes in a Parts-Pak clear plastic box with resealable lid.
One year quality guarantee.

Includes

(1) Aluminum Safety Spinner Nut

Specifications

Shaft Size: 5/16-24
Length: 1"
Diameter: 7/8"

Comments

Also available in heavy brass (GPMQ4641).
Tighten nut with a screwdriver, ball driver or steel rod.