7孔打孔机，孔直径为6mm等,孔距：24.5-24.5-19-19-24.5-24.5,    29.67-29.67-29.67-29.67-29.67-29.67,  25.4-25.4-38.1-38.1-25.4-25.4,    25.4-25.4-57.2-57.2-25.4-25.4,一次性可打10张复印纸。 专利号:200720108633.X