JLC hired external collaborators for this product, but it's an official product of the maison. The designer was Samuel Wühl. Here you can see its page on the 1998-1999 Livre de la Manufacture.
A Reverso ring using Calibre 101 , which I was fortunate to acquire at an auction held by Christie’s a few years ago. These rings were made in various metal and stone combinations, in extremely small numbers (some claim fewer than 10), toward the end of the 1990s. One variant appears in the Jaeger-L
Much more subtle than the LM Sequential. A split hour may not be indispensable maybe but the hour register is often useful and the triple split is the only Lange chronograph to have it. I ended up wearing the LM Sequential much more than the TS but it is a comfort / perceived ruggedness / purely per