This is from the American Watchmakers-Clockmakers Institute 2010 Edition Handbook on Battery Number System. MR42 CITIZEN 28051 HSB Varta 502 214 W2

Fits and replaces: Bulova 218 Accutron Deep Sea model Accutron 48722 Accutron Bulova N1 Bulova N 1 Bulova Accutron 2182 Timex Type B mercury cells Varta V350H Varta 350 H Bulova 218 Watch Battery 1OL120 Energizer 344, AWI S10, Eveready 343, Eveready 344, Replaces the mercury Rayovac RW56, Eveready 350, 218 BULOVA, Renata 7, Renata 9,Energizer 344, EVEREADY 343, Bulova 242, Duracell D344 and WS12, 344/350, Maxell SR1136SW, Panasonic SR1136SW and WS-12, Rayovac 344 and RW36, Renata 34 and 12 and 350, Sony SR1136SW and 344, Varta V344 and 529 and 569, IEC SR42,and Misc. battery number SR1136.

Fits and replaces: EVEREADY MR42 UNION CARBIDE #343, Bulova 230 Watch Battery, Bulova 218 Watch Battery, Bulova 242 Watch Battery, Bulova 224 Watch Battery, Bulova 219 Watch Battery, 344 BAT., RAYOVAC 344 WATCH BATTERY, WH12NM, PANASONIC WATCH BATTERY #WH12N, caravelle wrist watch battery panasonicbattery #WH12NM, Caravelle, D344, V344, 242, SR1136SW, SR42, SR42L, 529, RW36, S10, 1133SO, Eveready No. 344, UCAR 344, Rayovac RW36, Renata 344(12), Renata 344, Renata 12, Varta V344/529, Varta V529, Varta 529, Mallory WS12, Berc SR42L, Omega 9923, Bulova 242, Waltham B, 344 WATCH BATTERY, 344 WATCH BATTERIES, ACCUTRON M7 WATCH .

Fits and replaces these mercury applications: 343, MR42, MR1136, 509, Bulova 218, Timex B, Citizen 28005, NP343, HG11, M08, 1154M.

The 344 or SR1136SW is used by Accutron watches as a 343 or MR42 replacement. Perfect in your Accutron 218, Accutron 230, Accutron 224, and Accutron 219 or the Omega f300. Mercury batteries have been outlawed because of toxicity and environmental concerns and are no longer available.

MOVEMENT/CALIBRE:

ETA 9362 ETA ESA 9362 ESA ETA 536.111 ETA ESA 536.111 ESA ETA 870.101 ETA ESA 870.101 ESA ETA 870.231 ETA ETA 900.231 ETA ESA 900.231 ESA ETA 952.101 ETA ESA 952.101 ESA ETA 952.121 ETA ESA 952.121 ESA ISA 1198 ISA ISA 1552 ISA 1422 ISA ISA 1198 ISA 1552 ISA 1553 ISA 1198 ISA 1165 ISA 1166