Traditional clamps for soundboards and backs. Available in two sizes, spool clamps are fast, safe, and indispensable in your shop.
The smaller violin/mandolin clamp opens to 1-3/4"; the large clamp opens to 5-1/2" for guitars or cellos. Repair shops should have several dozen of each size on hand for typical gluing jobs. Cork lining on the hardwood spools helps protect the instrument.