These 3/4"-20 thread axle nuts fit 500 / 650 c.c. Triumph motorcycles rear axle / spindle. This is the 'thick' axle nut, there is also a thinner one that fits the right side of the speedometer drive. Stock application there would have been three of these on you rear axle, one against the brake plate between the brake plate and swingarm and one on each end of the axle. Brand new, zinc plated. Sold individually. Stock part number is 82-1747.