The Royal Oak Extra-Thin 15205BA.OO.1240BA.01 was introduced in 2015 as a limited edition of 50 pieces for the 50th anniversary of Singapore retailer The Hour Glass. It was the first Royal Oak to [again] use yellow gold - a material notably absent in many collections for a number of years, with pink & rose reigning supreme.
Slim (3.05mm) self-winding movement, originally created by Jaeger-LeCoultre and used by Audemars Piguet, Vacheron Constantin and Patek Philippe.