Omega 310.23.42.50.99.001 Speedmaster Moonwatch Professional 42mm Steel Senda Gold on Alligator StrapThe Speedmaster Moonwatch is one of the worlds most iconic timepieces. Having been worn by astronauts on all six moon landings, the legendary chronograph is an impressive symbol of OMEGAs pioneering spirit.This 42 mm bi-colour model in stainless steel and 18K Sedna Gold features sapphire crystal glass on the front as well as on the caseback. Inspired by the 4th generation Speedmaster style worn on the moon, it includes an asymmetrical case with a black ceramic bezel ring, with its tachymeter scale and famous dot over ninety in OMEGA Ceragold.The PVD-treated 18K Sedna Gold step dial is sun-brushed and presented with applied OMEGA logo and indexes, 18K Sedna Gold hands, and black coated subdials including a small seconds recorder, 30-minute recorder, and 12-hour recorder.The watch is worn on a black alligator strap and is powered by the OMEGA Co-Axial Master Chronometer Calibre 3861.