Adjusting Tightener Arm Length to Hole Center 2 in For Shaft Thread Size 3/4 In.-10 Includes Tightener Shaft No Mount Base Length 4 1/2 in Mount Base Width 5/8 in Mount Hole Diameter 3/8 in Overall Length 2.06 in Shaft Diameter Not Applicable Shaft Length Not Applicable Shaft Thread Size 3/4 In.-10 Thread Length Not Applicable Compatible Idler Pulley Grainger Part Number 6AGN9 (Timing) 6AGP1 (Timing) 6AGP2 (Flat) 6AGP3 (Flat) 6AGP6 (V-Belt) 6AGP7 (V-Belt) 6AGP8 (V-Belt)