This oil is for all manual gear Vespas as well as in the gear box of Lambretta C/LC/D/LD etc.
The Vespa engine is quite different when it comes to oil if you compare to a Lambretta and the amount of oil is important that it’s just up to the oil level hole, if you fill too much it will leak out from the gear box breather and if you will fill too less, your clutch will be sad.
Various models use various amount of oil. For all full frames (PX, S, GT, GTR, P, TS, 150, GS, GL, Sprint, SS180 and Rally) one bottle is sufficient. For large frames (pre 1959) one bottle is usually sufficient. For small frames (all 50cc, PK, SS 50-90, Vespa 125, Primavera and ET3) usually more than one bottle is needed.