This is an OMEGA Speedmaster Moonwatch Professional Master Chronometer Chronograph Manual-winding 310.30.42.50.01.001. This is the current Speedmaster Professional, equipped with the Omega Co-Axial Master Chronometer Caliber 3861. The overhaul frequency for this movement is said to be once every 10 years. It has a 5-year warranty, so it is currently under warranty. (I have received a free inspection and movement adjustment, and I have the details) There are minor scratches from use, so please consider this before purchasing. The crystal is Hesalite (reinforced plastic). The included straps are the original bracelet and a Forstner "beads of rice" style bracelet. ref. 310.30.42.50.01.001 Serial: 829※※※※※ cal. 3861 Manual-winding Warranty card date: 2021.7.20 Size etc. *Measured with calipers Width: 42mm (excluding the crown) Length: 47.2mm (lug to lug) Thickness: 13.9mm Lug width: 20mm Accessories Warranty card, Master Chronometer certificate card, Pictogram card, booklet, inner box, outer box, 6 spare links (approx. 5mm per link) *The current wrist size is adjusted to about 17cm, so it can be extended by about 3cm. Other accessories include a Forstner "beads of rice" style bracelet (currently adjusted to 14cm) and 8 spare links (approx. 5mm per link). 310.30.42.50.01.001