Self-Adjusting Tensioner Arm Rotation 45 Degrees For Chain Number 40 For V-Belt Size Not Applicable Pulley Outside Diameter 2 63/64 in Sprocket Outside Diameter 2.98 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 3/8 in Overall Depth 1.67 in Overall Length 6.37 in