 The Gyromax is a 'free sprung' balance, meaning there is no regulator on the wheel's balance spring for adjusting the watch's rate, so the collets are used for adjusting both poise and rate.Swiss patents were granted to Patek Phillipe for the Gyromax balance on May 15, 1949 and December 31, 1951, and the balance was first used in watches in 1952.Another balance wheel with a similar design is the Rolex Microstella.