Form movements from ETA are rather rare, the last one might have been factured in the 1950ies. The caliber 2340 described here, which contains a nickel screw-balance, but is missing a shock protection, is from that time.
|Size:||5 1/2 x 8 3/4'''|
|Number of jewels:||15|
Nickel screw balance|
|Balance bearing / direction hairspring:||Counterclockwise|
|Adjust mechanism:||Long regulator arm|
Flume: 1957 46|