Tank series: which gas lift is which?

So my tank series chair showed up today and I am in the process of assembly. The tank comes with two gas lifts one goes lower to the ground one goes higher, however all the documentation refers to them as 100/40 and 100/60 but the gas lifts themselves have part numbers of SP/0309 (white top) and SP/0310 (red top). Anyone know which is the "short one" and which is the "tall one"?