The 42mm Zenith El Primero Chronomaster Power Reserve utilizes the caliber 4021 movement, which incorporates a silicon escape-wheel and lever that can be viewed via the dial aperture and case back. A power reserve indicator is located between 5 and 8 o'clock.
Movement Type
Automatic Chronograph
Caliber
El Primero 4021Jewels
39
Reserve
50
Frequency
36000
Hands
Small Seconds
Shape
Round
Material
Stainless Steel
Glass
Sapphire
Thickness
14.05 mm
Diameter
42.00 mm
Water Resistance
100.00 m
Dial Color
Silver