oil seal 166 Series Fit 1/2" 5/8" 3/4" 7/8" 1" Shaft Seal With Single Coil Spring mm - Inch 12.7mm = 1/2" 15.88mm = 5/8" 19.05mm = 3/4" 22.23mm = 7/8" 25.4mm = 1" Model Number : M5/6/8/10