Dustite Dust Cap Wheel Nut Indicators 19 mm Long Reach • Yellow • Dustite® Benefits Include: Instant Visual Indication of Nut Movement • Melts at a Specific Temperature to Highlight Problems With Brakes Overheating or Any Bearing Defects • Protection From Weather, Corrosion and General Wear and Tear • Supports Fleet Safety Checks • Cost Effective • Easy to Implement