ETA 6497-1 skeleton 16.5 ligne movement. Blue screws (including case screws) Incabloc shock protection. Subsidiary seconds at 9 o'clock. The best skeletonization of the ETA movement (semicircular pallet fork bridge) which looks much better looking through the movement. Not an asian knock-off. Running strong. Servicing is still strongly recommended in spite of it running well as I don't know its history and it hasn't been serviced recently. If in doubt, ask me to measure the balance amplitude and I can do that.