Thread Size: 5/16-24

Superior vibration dampening and wind performance.
Almost no sag even when loaded with a large number of weights.
Aerodynamic design with ring grooves giving superior X and Y axis vibration dampening.

- Superior vibration dampening in all axes...X, Y, Z - Equally spaced ribs around the circumference for superior Z-axis vibration reduction - Arc-shaped scalloped rings with the smallest diameter grooves in the middle for superior x-axis and y-axis vibration reduction - Strong proprietary rubber