Self-Adjusting Tensioner Arm Rotation 45 Degrees For Chain Number Not Applicable For V-Belt Size A Pulley Outside Diameter 3 in Maximum Tension Force 30 lbf Arm Material Aluminum Base Diameter 2.76 in Features Alloy Steel Compression Springs Self-Adjusting Tensioner Eliminates Need for Regular Manual Retensioning Includes - Minimum Tension Force 0 lbf Mount Hole Diameter 13/32 in Overall Depth 1.67 in Overall Length 6.39 in Product Type Rotary Tensioner Idler Pulley Assembly