Audemars Piguet was inspired to start working on tantalum from the King of Spain that had his armor blue steeled. The manufacture was the first manufacture to produce pieces in a tantalum case. Renowned to be very diffi cult to work with tantalum has the advantage of being close to the weight of gold and can be worn by individuals that are allergic to steel. Made by the fi rm in tantalum tantalum and steel and tantalum and pink gold the pieces were made in a limited production and have an instantly recognizable look.