Other than the Gerni Super 145.2 I'M NOT CERTAIN WHICH of the Gerni models and the corresponding Nilfisk-ALTO models it will suit.
Being bluntly honest, I don't know the difference with these different pistol grips, other than some are G3 and some are G4 etc.
We are frequently asked "Can we get a repair kit for these pistol grips?" And at the time of writing, to our knowledge on the most up to date literature we have, see the "O" ring kit PN. 128470198
We suggest you try Pn. 128500668 however, there is little official information about the number change, because both are used by Nilfisk, and if we order THIS part number, we are supplied with 128500668
See the consumer accessory book HERE
Maximise the saving on postage and buy some of the related parts below, such as a hose, filters for your Nilfisk or ALTO vacuum cleaner, or a new floor tool and hose.
At the moment standard postage within Australia, is capped at a maximum of $20!