Introduced in 1986 together with its sister model reference 3970, the reference 3971 represents a rare chance to see the handiwork of Patek Philippe, through the transparent caseback, having succeeded the legendary reference 2499 that features a solid case back. Initially offered with a snap on back, it was later revised to a screw down version to improve water resistance, such as the example offered here. Preserved in excellent overall condition, the case has clearly visible hallmarks on 3 lugs and the rarely seen Patek Philippe case marker stamp - number 28 in the key Poincon de Maitre - punched on the lower left lug.

The left side of the case has developed a highly attractive patina which shows the level of preservation for this particular example. The dial is also in immaculate condition and features the feuille hands and rectangular markers from the earlier series of the reference 3970. With less than 300 pieces made of the reference 3971E, the reference is even more of a collectors item when accompanied by the original certificate, presentation box, and fresh to the auction market, such as the watch offered here.