Tanks, lids, and covers hold the fluids the machine works with and keep the fluids you don't want out of places they'd cause trouble. When one cracks or the lid doesn't seat right, you get slow leaks — and slow leaks are the kind of problem you don't notice until you find a puddle under the machine every morning.
This is the genuine Nilfisk Advance OEM LID SKIP HOPPER 105G R2004, part number 4083100743, brand new in the box. Factory-fit means the plumbing hookups, mount points, and sealing surfaces all line up — the whole thing goes back together the way it came apart.
Aftermarket tanks that are "similar" tend to be similar right up until the fitting hookup on the back, and then it's zip ties and prayers.
Not sure this is the right tank for your machine? Send us the model and serial and we'll confirm the fit.