Felsa was a manufactury, which was known for their quality movements. The large caliber 465 with 11 1/2 lignes was one of them. It has got a direct driven center second hand and a kind of sandwitch construction, which allows larger sizes of the parts and thus higher precision and longevity. Several axes are also beared under cap jewels.
A speciality of this movement unfortunately cannot be seen in the pictures: The pallets of the anchor are made of an almost translucent material. Probably this was better (and more expensive) as the normally used synthetic rubies.