Check the listing for details. StewMac Spool Clamp - Set of 6. Condition: New. Listed at 59.51 USD. The classic spool clamp with a new twist: this is a big improvement! The simple spool clamp—two short wooden spools on a long threaded bolt with wingnut tightening—has long been a familiar tool for soundboard/back assembly and repair. We wondered, could it be made faster and less fiddly to use? (After all, glue won't wait forever.) The answer came from clamps refined by StewMac's Don MacRostie for use in his own shop: replace the wingnut with a finger-friendly hardwood handle. Now a quick spin of the lower spool closes the clamp, and an easy turn of the handle applies the pressure. Better than the classic spool clamps: Smooth and precise pressure adjustment Sturdy hardwood spools are lined with protective cork Tubing on the rod protects the instrument from scratches Clamp dimensions: Maximum opening: 5-1/4" (133.35mm) Clamping depth: 9/16" (14.29mm) Handle length: 4" (101.6mm) These high quality clamps are sold in sets of 6. Complete acoustic guitar assembly typically requires at least four sets. For mandolin, violin and ukulele assembly, simply trim the protective tubing as needed for tighter closure.