Sioux rivet guns are among the finest in the industry. They are used extensively in military and civilian aircraft production plants. These guns are built sturdy for rugged use and have excellent balance for fatigue-free riveting. A newly patented metering trigger gives you full control from start to full power for riveting. Uses all rivet sets and accessories having a .401 shank. Includes a beehive spring. Manufactured by Sioux Tools, Inc. 5/32" maximum riveting capacity.