The Audemars Piguet Royal Oak Chronograph 26239 was introduced in 2021. For this generation of Royal Oak Chronograph, Audemars Piguet replaced the caliber 2385 with the in-house caliber 4401, visible through the see-through case back. Reference 26239BC.GG.1224BC.02 has a White Gold case with frosted finish, and a Black dial.