XC8 option has adjustable stroke in the extend direction; XC9 option has adjustable stroke in the retract direction; XC10 is dual stroke with 4 positions (doulb rod type); XC11 is dual stroke with 3 positions (single rod type); XC12 is a tandem dual power cylilnder (single rod type); Bore sizes (mm): 40, 50, 63, 80, 100