Self-adjusting tensioner Arm Rotation 70 Degrees For Chain Number Not Applicable For V-Belt Size B Pulley Outside Diameter 5 in Maximum Tension Force 42 lbf Arm Length to Hole Center 4.5 in Arm Material Aluminum Base Diameter 3.34 in Features Automatically Take Up the Slack and Avoid the Risk of Over-Tensioning Drive Components to Enhance Overall Drive Operating Efficiency Housing Material Aluminum Includes RT3001 Tensioner VA5001 Pulley Minimum Tension Force 0 lbf