The LW.01M and LW.01A are powered by a https://www.apwx.co.uk/product-category/royal-oak-offshore/ ETA 2000.M1 modified by Schwarz-Etienne for MING, which were picked with an attempt to make a thin watch for the brand's fourth anniversary. That idea morphed into a challenge to make a light watch, then the lightest, but all that was delayed with a years-long https://www.ctrwx.co.uk/Collection/ballon-de-cartier/ years exhaustive amount of testing and https://www.omgwx.co.uk metallurgic experimentation.