Tool-free quick change design allows for instant hand tightening without a wrench, reducing downtime. Versatile flange nut kit includes a 9mm silver D-ring nut for tight spaces and a 13.5mm black knurled nut for maximum stability. Heavy-duty self-locking build crafted from heat-treated carbon steel, withstanding 12,000+ RPM. Compatible with standard 5/8"-11 UNC grinders, fitting most 4-1/2", 5", 7", and 9" models. Optimized for flush and heavy cuts, ensuring a secure fit for thin cutting wheels, flap discs, and thick abrasive accessories., Weight: 0.24471311082 Pounds, Manufacturer: Kueohse