A mid 20th Century Swiss split seconds chronograph in a stainless open face case. Gilt three quarter plate keyless movement with going barrel. Plain cock with polished steel micrometer regulator, small fast beating compensation balance with blue steel overcoil hairspring. Club foot lever escapement. Signed and numbered white enamel dial with split centre seconds chronograph and 30 minute record. Each seconds division is subdivided into tenths, the marking alternatingly divided inside and outside the ring. Continuous subsidiary seconds, Arabic numerals, blue steel hands. Substantial plain stainless steel open face case, clip on cuvette and back with engraved serial number, Omega maker’s mark.