Armstrong 64-700  3/8-Inch Drive 12 Point Metric Torque Wrench Adapter Set, 4-Piece The Box End Wall Thickness is Specially Designed to Provide Strength While Still Allowing Ample Room for Access to Reach Restricted Fasteners. Measure Exactly 2 Inches From Center of Adapter Opening (Fastener) to the Center of Square Drive for Easy Torque Calculations Formula to Determine Torque Wrench Setting Using A Torque Adapter This Calculation Assumes That the Attachment is Aligned with Torque Wrench Handle When Torqueing Fastener