3a all threaded stud thread class 0.875" all threaded stud thread length 2.500" overall length 2.000" overall width 28 all threaded stud thread quantity per inch principal parts, drive quill, contractor assy, metal weights, bronze contacts rectangular unf all threaded stud thread series
2b single threaded hole thread class 0.500" single threaded hole thread length 18 single threaded hole thread quantity per inch uns single threaded hole thread series
4.250" overall length 3.125" overall width principal parts, coil springs, contact assy, metal frame with lever action actuating mechanism, brass contacts