Turn-O-Graph Thunderbird 16263 — Two-Tone

Rolex 3135

Successor to the 3035 with a full balance bridge, MicrostellaMicrostellaRolex’s system of small adjustable screws or nuts on the balance wheel, used to change its inertia and regulate the watch’s rate. Introduced as screws in 1957 and developed into nuts in 1983, it allows rate adjustment with the movement still cased. The name identifies the Rolex system, rather than every adjustable-inertia balance. free-sprung balanceFree-sprung balanceA balance regulated by changing its inertia with adjustable weights or screws, while the balance spring’s active length remains fixed. It dispenses with the conventional index regulator that changes the spring’s working length. The term describes the regulating arrangement, not a particular hairspring material or certification. and longer power reserve; later examples received the blue Parachrom hairspring. Used in the Sea-Dweller 16600, Submariner Date 16610 and Datejust.