Introduced in the early 1970s, the Jaeger-LeCoultre Memovox “Speed Beat” Ref. E875 marked a pivotal evolution in the iconic Memovox line. First launched in the 1950s, the Memovox, Latin for "voice of memory", was celebrated for its mechanical alarm complication, a practical yet charming function that quickly became a signature of Jaeger-LeCoultre. With the introduction of the Speed Beat series, and particularly reference E875, the brand brought this mid-century innovation into the modern era.

The reference E875 houses the Caliber 916, introduced around 1969, the first high-frequency automatic alarm movement developed by Jaeger-LeCoultre. Beating at 28,800 vibrations per hour, the “Speed Beat” nickname refers directly to this increased frequency, which enhanced precision and reliability over previous Memovox movements. Unlike its predecessors, Caliber 916 also featured a full rotor, a significant improvement in winding efficiency compared to the earlier bumper rotor calibers. Reportedly 7731 watches were produced with Calibre 916.

The stainless steel case measures a robust 37mm. Two crowns, one for setting the time and winding the movement, the other for setting the alarm, flank the case at 2 and 4 o’clock respectively.