Zenith was the second company in the world (after Eterna) which offered alarm wrist watches even before the second world war. Same as Eterna also Zenith used pocket watch movements in those watches. But again in the peak of alarm movements in the period of 1950 - 1980 Zenith never developed any own alarm movement nor issued any Zenith alarm watch with some other movement. That changed in 2005, when Zenit launched state of the art watch Zenith Grande Class Traveller Repetition Minutes with Zenith 4031 alarm movement based on Zenith El Primero chronograph movement. Chronograph movement was upgraded with GMT, minute repeater, big date and double power reserve complications. 

In 2009 simplified alarm movement version Zenith 4046 was integrated in two models of the Zenith watches - Class Traveler Open Multicity and pilot Doublematic. This movement lost minute repeater complication and only alarm power reserve is present (alarm is hand winding). It is obvious that of course two spring barrels are used with two separate crowns.

Instruction manual:

Crown and the pusher on the right side of the case are standard Zenith El primero functions for time, date and chronograph functions.

Left upper crown is only used for turning inner bezel.

Left lower crown is an alarm crown.

In position 0: Winding the alarm. Indicator between 6.00 and 8.00 shows the winding status.

In position 1: Setting the alarm hand.

Button inside the crown: Alarm On/Off. Status of the alarm shows indicator above 8.00