The L836.6 was designed exclusively for
link Longines in a collaboration with ETA. While not technically in-house I'd still call this in-group since both Longines and ETA fall under the Swatch Group's umbrella. When considering a dive watch whether the movement is in-house in-group or "off the shelf" it doesn't matter. What matters is that it works as advertised that
link it doesn't give you any issues and that it's
link accurate I mean it is a watch.