The Max Bill Chronoscope series watches offer fully automatic/ self winding mechanical movement J880.2 with display for date, Chronoscope with second stop, luminous hands and appliques. 40.0 mm stainless steel case. Convex hard Plexiglass with Silcralan coating. Calfskin strap with stainless steel buckle. Waterproof to 5 atmospheres. Being automatic means it derives its energy from the motion of the wearers arm, and therefore does not require winding or batteries. Chronoscope (sometimes referred to as Chronograph) refers to timepieces equipped with a stopwatch function. The 027/7800.00 model features a tan calf leather strap, white face with hour and minute markers and numerals. 10 micron 18 carat gold plated case. Max Bill was one of the most unusual artists of our time. A Bauhaus student of Walter Gropius, he is acknowledged for his outstanding works as an architect, painter, sculptor and product designer and has left behind a extensive portfolio of creations. This includes one of the most fascinating watch series ever designed â" the wall clocks and wristwatches he created for Junghans. The collaboration between Junghans and Max Bill began in 1956 with his first wall clock followed by a series of wristwatches in 1961, which have become true design classics. Manufactured by Junghans Germany. Every watch comes with a 2 year manufacturer warranty.