Tachometer-dwell Test Set

A set of one or more instruments, used for measuring the distributor cam dwell on internal combustion engines employing battery distributor ignition systems, and as a tachometer to measure the revolutions per minute of both battery distributor and magneto ignition system type engines. Excludes tachometer, electronic; tachometer, stroboscopic; tachometer, electric, nonself-generating and tachometer, vibrating reed.