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