MAS (Motocicli Alberico Seiling) was an Italian motorcycle manufacturer from 1920 until 1956 It was founded by Alberico Seiling, a successful motorcycle designer. Early machines had 148cc, 173cc and 244cc ohv and sv engines with large outside flywheels. Production concentrated on budget bikes. Based in Milan, it offered many model thru the 30s. During WW2, it supplied 500cc singles and 175 two strokes to the Italian Army.
Post war, they came out with a 122cc with unique air cooling along with some 175cc OHC bikes, however these sold in low numbers and the factory was forced to close in 1956.