7/8"-9 Zinc Plated Grade 8 Steel Coarse Thread Nylon Insert Lock Nuts (3 pcs.)

Diameter: 7/8"
Diameter 2: 1-7/16"
Thickness: 1"
Material: Steel
Finish: Yellow Zinc
Driver Type: 1-5/16" Wrench
Thread Size: 9 (Coarse)
Hardness: Grade 8
Style: Nylon Insert
Type: Lock Nut

Box of 3.

A lock nut is a nut that resists loosening under vibrations and torque.