When the case enters the Assembly Department, it is meticulously checked. The dial and movement, together with the casing ring, are fitted to the inside of the case. Thereafter, the crown and stem are inserted and the movement is then secured with screws. A special screwdriver is used to attach the oscillating weight to the movement. The case back is then closed using a dedicated machine. Each case back is then engraved with its own identifying marks using a laser. The watch is now ready for its final test. Watchmakers use tools to manually affix straps or bracelets to the ‘watch head’. Once again, absolute concentration is needed to avoid scratching any parts and the clasp is checked to ensure it closes securely.