In the seventies, Ronda SA from Lausen in Switzerland launched a series of movement, that all based on the caliber Ronda 1211 and was available in different qualities, with different escapement types and with different functions.
The Ronda 1223 was on the low end in terms of quality (only one jewel and completely raw movement plates) and on the type of escapement (pin lever escapement). But it contained a rather rare function, an alarm mechanism. It was realized by a module which was mounted on the dial side, while there rest of the movement remained untouched, except the balance cock, which got a small insert for the alarm winding mechanism.
The base movement is a simple pin lever movement with directly driven center second and a nickel balance, which is secured in a KIF-Protechoc system. Unlike in other movements, there are no jewels for the balance bearings, but only two metal bearings.
The alarm mechanism mainly consists of a mainspring, which seems to originate from a ladies' sized movement and whose one end is fixed on the dial plate. By turning the alarm crown clockwise, this spring is wound; by turning counter-clockwise, the alarm time is set counter-clockwise.
On the selected time, the alarm disc falls down a little bit and releases the finger, which previously blocked the alarm hammer.