Bought this one mistakenly. You're never too old to pay noob tax.. Nevertheless, it's a nice original Omega SM300 Flat Feet Crown, correct 24 teeth and measures (approx 6.75 mm wide/3.40 mm height.), matching for Ref. 2913/14577/165014 Comes with a Stem matching Cal. 550/552, don't know if this stem also fits a 501 (2913), but it can easily be removed in case you need a different one. Asking what I payed for it. 300 Euro including shipping. Me and the Crown are located in Germany. Thanks OF for the space Pictures: