REF. 3971ER, MOVEMENT NO. 875'480, CASE NO. 2'870'009, MANUFACTURED IN 1989

In 1986, Patek Philippe launched a new generation of the perpetual calendar chronograph wristwatch, designated reference 3970 and much rarer reference 3971, replacing the hugely successful reference 2499. The main difference in the movement was the arrival of the new Lemania base ébauche which replaced the Valjoux movement used for the previous 50 years. Only a small number of reference 3971 are available as it was soon discontinued in 1990, when the third series of reference 3970 was launched with a spare crystal case back.

Reference 3971 is illustrated in: Patek Philippe Museum - Patek Philippe Watches, Vol. II, p. 307.