Audemars Piguet Royal Oak Jumbo Openworked Yellow Gold 16204BA

This Royal Oak Jumbo Extra-Thin Openworked in 18k yellow gold displays the full mechanical movement beneath the dial. Reference 16204BA.OO.1240BA.01 makes every bridge, gear, and jewel visible through sapphire crystal.
AP’s openwork approach defines this piece. The entire is dial is skeletonized to reveal bridges, gear trains, and balance structure floating within the octagonal case. Every bevel, edge, and cutout receives individual hand-finishing. 
The watch wears comfortably despite full yellow-gold construction. At 39mm across and just 8.1mm thin, weighing 191 grams, the integrated bracelet distributes weight evenly across the wrist. The bracelet maintains strong presence. AP’s brushed and polished finishing creates visual contrast where solid surfaces meet the openworked dial.
This reference appeals to collectors who value mechanical artistry as the complication. The movement itself serves as the visual centerpiece. The execution delivers pure Royal Oak design vocabulary.
The 16204BA combines Jumbo proportions, full openwork execution, and all-yellow-gold construction in a single reference.