Thread Diameter: 8.5mm / 5/16";Outer Nut Size: 8.5x 30 x 7.7mm / 0.33" x 1.2" x 0.3"(Inner Dia*Outer Dia*T) Inner Nut Size: 10 x 30 x 6mm / 0.4" x 1.2" x 0.24"(Inner Dia*Outer Dia*T);Material: Metal Product Name: Inner Outer Flange;Fit Model: 9523NB Grinder Color: Black , white Tone;Weight: 40g, Weight: 0.19731372449 Pounds, Manufacturer: Jaywool