Gaskets and seals are the small parts doing the invisible work — keeping air out of the vacuum path, water out of places it shouldn't go, and solution flowing where it's supposed to. Nobody thinks about them until one fails, and then you're chasing a suction problem that turns out to be a two-dollar piece of rubber.
This is the genuine Nilfisk Advance OEM WSHR-SEAL 2.25 OD ZINC PL, part number 2-00-03797, brand new in the box. Before you replace a motor for weak pickup, check the gaskets — an air leak kills suction just as fast, and it's a lot cheaper to fix than a motor.
Rule of thumb: any time you have that part of the machine apart, replace the gasket while you're in there. The part costs a couple of dollars; the labor to open it up again costs a lot more.
Not sure this is the right gasket for your machine? Send us the model and serial and we'll confirm the fit.
