1/2″-20 UHP Yellow Zinc Plated Grade 8 Steel Thin-Profile Nylon-Insert Locknuts
X1Tools Ultra-Hi-Performance Yellow Zinc Plated Grade 8 Steel Thin-Profile / Low Profile Nylon-Insert Locknuts / Stop-Nuts are made to resists loosening due to use or vibration without damaging threads thus prevent a fastener from backing off.