MIDWEST? 3 in & 6 in Interchangeable Blade Straight Handle Seamer Sets include both 3in X 11/4 in and 6in X 11/4 in forged interchangeable blades and a changeover hex key on a carded set. Blades have 1/4" sight graduations. Commonly used by sheet metal and HVAC/R technicians to bend and form coldrolled and stainles steel, as well as galvanized, copper and aluminum. MIDWEST? Interchangeable Blade system allows for other length blades to be installed ( 3in & 6in forged blades / 5in, 9in, and 15in aluminum blades). Equipped with KUSH'NPOWER? compound leverage handle action with patented (US D718,602, D719,808) handle grip design multiplies handle force while providing a soft, sturdy and comfortable grip. Made in the USA!