Reference E855 is the Memovox Automatic Calendar introduced in 1960: a 37 mm stainless steel case built in three parts with a screw-down ring, a silver sunray-brushed dial with a date window at 3 o’clock, and Jaeger-LeCoultre’s calibre 825 inside. That movement — a “bumper” automatic with an alarm and date, introduced in 1959 and made until 1969 in some 67,000 units — was the first self-winding alarm calibre with a calendar, and its hammer strikes an off-centre post soldered to the case back to ring.

The Polaris name belongs to the diver that grew out of this family: the 1965 E859, a 42 mm compressor-case dive watch with an internal rotating bezel, three crowns and water resistance of 200 metres, whose triple-layer case back with holes was patented to let the alarm sound through underwater. That model kept the calibre 825’s alarm-and-date layout and became the watch collectors mean by “Memovox Polaris”, while the E855 remained the dressier 37 mm automatic alarm.

Enthusiasts regard the 37 mm E855 as one of the best-proportioned Jaeger-LeCoultres of the period, and clean examples with original dials trade in the low thousands — Chrono24 listings for steel E855s run from roughly $2,300 to $6,000 — while Polaris dive models sit far higher. Neither the E855 nor the 1960s Polaris is still made, but the badge is very much alive: Jaeger-LeCoultre relaunched the Polaris line in 2018 with modern automatic, date and alarm models.