Features: The Strato U-Line is optimal when extreme precision is required (measurements in the µ range) Easy, fast & extremely precise positioning. One knob allows for simultaneous tightening / releasing of all 3 joints. Uses a maintenance-free, mechanical central tightening system. Quick, stepless lock. High-quality, red anodized, light alloy. Swiss made. ROHS and REACH compliant. Indicator holder and base is not included. This listing is for 1 arm. Still need an Indicator? Check out our selection here. Dimensions (mm) [see 2nd picture]: L=204 L1=116 L2=88 Threads [see 2nd picture]: M1=M8 M2=M6 Fisso Strato U-Line A-20 Articulated Indicator Gauge Holder Arm is the best choice when extremely high precision measurements are needed quickly and easily. After you attach it to a machine or base and add the adjustment / gauge holder, operation is easy. Just position it, twist the knob and you're good to go. Still have questions? You can contact us, or take a look at the Fisso Resource Center.