A small watch with big price tag - Jaeger-LeCoultre, 101 caliber. The 101 caliber was created by JLC in 1929.

Elizabeth II of England was wearing her 3rd 101 when she was crowned. Why the 3rd one ? She lost 2 ! This may be the best proof of the caliber's small size - 14 x 4.8 x 3.4 mm and only weights 1 gram with 88 parts.