There are 10 styles in the Westclox Pocket Ben Style Series
Dates made: 1915 - 1927
Oval bow and pendant.
Dates made: 1927 - 1929
Oval bow, oval pendant, silver-plated metal dial.
Dates made: 1929 - 1931
Oval bow, rectangular pendant, silver-plated metal dial.
Dates made: 1931 - 1932
Silver-plated dial with circular rings in center.
Dates made: 1932 - 1933
Two-toned dial with silver center. Note: The center often appears to be gold (instead of silver) due to yellowing of the crystal.
Dates made: 1933 - 1942
Plain silver plated dial or black luminous dial
Dates made: 1946 - 1960
Round top bow, Dauphine style hands (small or sweep second hand)
Dates made: 1960 - 1980+
Push button at bottom to turn on light.
Dates made: 1967 - 1969
Trapezoidal bow, dauphine hands
Dates made: ca. 1990