In their chronometre grade pocket watch movements (typically the 21 jewel version of the movement). It was typical in the 1900-1920 time period to have several variants of the same basic movement with the lower grade ones using 15-17 jewels, less decorated with the plain regulator, and either not regulated or regulated in two positions to the higher grade versions which had 21 jewels, upgraded parts and a higher level of finishing, chronometre regulation and upgraded regulators - either this snail type one or a swan neck regulator. The chronometre grade movements would also typically have fancier dials.