Longines L888 movement has many versions

Longines L888 movement has many versions
L888 series movement is a new generation of main movement of Longines, which replaces L619 movement based on ETA 2892-2 which has been in service for many years. Compared with the latter, the performance of L888 series movements has been improved in many aspects, which is more in line with the use needs of modern movements. Longines L888 series movement has been developing and improving since its debut at the end of 2015. Now it has formed a variety of versions, with slight differences between different models.
L888 series movement is a special model provided by ETA for Longines, and its name is ETA A31.L02 in ETA. Regardless of the version, their common parameters are 25.6 mm in diameter, 3.85 mm in thickness and 21 drill holes. The L888 series movement not only has a certain "kinship" with ETA 2892 in the structural principle, but also has made many improvements: for example, the use of non-clamping hairspring and weight fine adjustment, and the reduction of the diameter of the automatic spindle to improve the winding efficiency. In addition, the L888 core vibration frequency adopts a unique 25200vph (3.5hz), which can be exchanged for long-term dynamic storage by properly reducing the vibration frequency.
L888.2 movement is the early model of the series, which has been carried in many series, and is one of the widely used versions. The L888.2 movement is characterized by the use of metal hairspring, which is divided into conventional models with calendar display function and non-calendar models (No Date, abbreviated as ND). For example, the classic replica series "Little Freckles" L2.819.4.93.2 uses the ND version. With the introduction of the silicon hairspring model L888.5, L888.2 has completed its mission and has gradually withdrawn from the list of current products. However, there are still many watches with this movement in the secondary market.
However, the L888.2 movement also exposed some problems during its long-term use, and the optimized model L888.3 came into being. In terms of parameters, the improvement of the movement is not obvious, which can be understood as an improved version of L888.2 calendar spring. Because it is only a transitional model, there are not many products with L888.3 movement, and the Comcast L3.784.456.9, known as "Black Knight", is one of them.
If the L888.3 upgrade is only a minor repair, then the real major change will be L888.4. The unique feature of this model is that it is equipped with silicon hairspring and has passed the certification of COSC Observatory, which is the highest configuration of the whole system. Silicon hairspring is one of the popular configurations of new products in recent years. With the popularity of electronic devices, the possibility of our exposure to magnetic fields in our daily life is increasing, especially the application of wireless charging technology, which makes mechanical watches exposed to the risk of being magnetized all the time. One of the effective ways to enhance the anti-magnetic performance of the movement is to use non-metallic hairspring, which can prevent magnetic deformation to a certain extent.
At present, most of the watches equipped with L888.4 movement are the pioneer series, which is mainly based on the certification of the observatory and printed with the word "Chronometer" on the panel.
It is not difficult to find that the new model is always improved on the basis of the old model, such as L888.3 improved calendar spring, L888.4 adopted silicon hairspring and passed the certification of the observatory. However, the L888.5 movement is an exception: compared with L888.4, it does not have the certification of COSC Observatory, but still retains the silicon hairspring. Therefore, the L888.5 movement is more like the upgraded version of L888.2, which is widely used in various new products. For example, the famous craftsman series "190th Anniversary Special Edition" carries this movement.