The OMEGA Speedmaster Moonphase Platinum Anti‑magnetic Watch and similar Moonphase models are part of Omega’s Speedmaster family — one of the brand’s most iconic lines, known for its history with lunar exploration and precision chronograph engineering. 

At its core, a moonphase watch shows the current phase of the Moon — from new moon to full moon — on the dial. This is a horological complication (a special function beyond telling the hours and minutes) that adds both poetic charm and technical sophistication to a timepiece.