This wristwatch is a limited edition of only 10 examples.The original Schaeffer watch is published in Audemars Piguet by Gisbert L. Brunner, Christian Pfeiffer-Belli and Martin K. Wehrli, p. 255.John SchaefferThe first Audemars Piguet watch with minute repeater was created in 1907 for the famous American industrialist John Schaeffer who wanted to personalize his watch by having Audemars Piguet position the letters of his name on the hour markers as well as wanting a unique shape of the watch, 'carré galbé' or cushion shape. This shaped case has been reintroduced by the Le Brassus manufacture, revising its dimensions slightly wider and a little rounder than the original.What is a minute repeater?A minute repeating watch tells the time both visually and audibly. A slide on the side of the case, usually near the #9, will activate two hammers in the movement. These hammers strike two gongs curled within the case. First one hammer strikes a gong of lower tonality; it will count out the hours. Then both hammers will strike both gongs alternatively to count out the quarter hours after that hour, and then the second hammer alone striking a gong of higher tonality will count out the minutes aftr that quarter hour. The repeating mechanism was developed by Daniel Quare. In 1687, he had patented a mechanism that sounded the hours and the quarters. The early repeaters used bells. At the end of the 18th century, two bent-wire gongs became the more popular mechanism. In 1892, the first minute repeater wristwatch was produced by Omega, a model with a round-shaped case.