Check the listing for details. 4pcs Recurve Bow Limbs Centerline Calibration Center Line Alignment Adjusaer. Color: Black, Condition: New with tags. Listed at 12.21 USD. Feature: 1. 100% brand new and high quality. 2. High quality material makes it durable. 3. Lightweight, easy to carry and install. 4. Simple and effective precision tool for the tuning of the bows. 5. With the aid of Limb Line Gauges you can check the arrow position on the bow and in respect of the position of the Sight Tunnel, limbs and the centre shot. 6. Limb Line Gauges are definetly an indispensable tool for every archer. 7. Easily align the string, limbs, arrow and sight. Specifics: Condition: 100% Brand New Color: Please refer to the picture Item Name: Recurve Bow limbs Center Line Adjustment Material: Plastic Net Weight: 6g/pc Suit For: all Recurve Bow Bow slice/handle calibration: 1. Firstly, the center line regulator is installed on the bow slice (two upper and two lower slices respectively) to observe whether the bow string position is on the center line. 2. Before calibrating the bow handle, you can adjust the bow string to the center line without lowering the bow string. 3. To adjust the bow piece to the left, loosen the adjustment screw on the left and tighten the adjustment screw on the right until the bow piece is in the middle. 4. Once the arch is centered, tighten the left adjusting screw again. Package Included: 4 * Limbs Line Gauge