Rockwood 580-8-613 Surface Bolt 8″ Length Dark Oxidized Satin Bronze, Oil Rubbed. Made of steel, stainless steel. UL listed for use on inactive leaf of a pair of 3-hour labeled fire doors. Includes a universal top strike and a mortise bottom strike. 1-1/8″ bolt throw, 1/4″ x 3/4″ bolt material.