Brookside Design Blueprint Hanging Clamps, 18-Inch, Set of 6 (BD-PC618) Set of (6) 18 inch extruded anodized aluminum blueprint plan clamps will hold up to 100 sheets securely without punching or stapling. Internal steel spring holds clamp open for easy loading. Heavy duty chrome plated steel wing knobs open and close the hanging clamp. Chrome plated steel clip includes a spring to clip onto pivot brackets. Includes snap-on clear plastic label holder. Blueprint and other large format document clamps are interchangeable with other manufacturers. Easy loading Extruded anodized aluminum clamps Each clamp will hold up to 100 sheets Limited lifetime warranty