ClampGAUGE Clamping Cauls - Achieve Accurate Pressure On Glue-Ups. Precision CNC machined from 6061 T6 aluminum barstock. Hard coat anodized and laser etched. Three Pairs - A Size ClampGAUGE = 5" long x 3/4" thick Aluminum. Three Pairs - B Size ClampGAUGE = 6" long x 3/4" thick Aluminum. Five Pairs - C Size ClampGAUGE = 7" long x 3/4" thick Aluminum. ClampGAUGE Chart For Proper ClampGAUGE Positioning. ClampGAUGE Retention Bands For Proper Alignment While Clamping. Suitable for 3/4" thick to 1" thick panels of any wood species. Made in the U.S. A.!