Arnold & Son has a fairly slim appearance with two tourbilion and two hour dials. It is only 8.35 mm thick and 43.5 mm wide, 0.01 mm more than Arnold & Son UTTE (Ultra Thin Tourbillon Escapement). The case is made of 18k red gold. The face is decorated with stripes in the Geneva motif. The two tourbillion apparatus will be held by a high bridge. HM is equipped with A & S8513 and has 90 hours of power reserve. Technically, HM is very similar to DBG, in that each watch face has its own wheel and escapement. The watch face is independently set to the minute and two tourbillons. Each will perform a job of an apparatus.