1/2"-13 Ultra H.P. Tuercas de seguridad amarillas chapadas en zinc grado 8 de acero con inserción de nailon
X1Tools Ultra-Hi-Performance Yellow Zinc Plated Grade 8 Steel 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.