 Similarly, the 900 series with bore sizes of 28mm, 30mm and 32mm, were known as 928, 930, and 932 respectively.The largest bore at 32mm was slightly larger than any previous Monobloc, and all were flange-fitting with stud-holes at two-inch centres.The Concentric design with non-protruding float chamber was both slimmer and shorter, enabling easier mounting to two-port cylinder heads.