Armin Strom Manual watches

The Armin Strom Manual is a hand-wound watch from the Biel maker, built around its in-house calibre AMW11 and issued as limited series named after the four elements: Earth, Water, Air and Fire. Each element is limited to 100 pieces, in a 43.4 mm case, 13 mm thick, with sapphire crystal front and back.

The AMW11 is a manually wound movement with a five-day, 120-hour power reserve. It measures 16½ lignes (36.6 mm), has 112 parts and 20 jewels, and beats at 18,000 vibrations per hour (2.5 Hz). Its screw balance, with a Breguet overcoil balance spring, is on show through the caseback. The movement is designed and made in Armin Strom's Biel factory; only the springs and jewels are bought in. The display is hours, minutes and small seconds, set off-centre on a dial built in several levels for depth. Water resistance is 50 m.

In 2012 Armin Strom followed up with the Manual New Generation, again a limited series for each of the four elements and again on the AMW11. The gears were reworked, the escapement was better integrated to maximise energy flow, and the movement decoration is done entirely by hand.

The element sets the case. The Air (TI11-MA.11) is titanium, the Fire (RG11-MF.90) rose gold and the Water (ST11-MW.05) stainless steel. The Earth (ST11-ME.90) is also steel, but with a black PVD treatment. Movement and dimensions are shared, so case metal and colour are what separate the four.