A genuine Karcher product no 4.590-105.0 / 45901050 from an authorised karcher dealer. We can find the exact part for you model using the number from the silver data label that is in the format of 1.xxx-xxx.
Karcher SG4/4 Steam Cleaner Safety Lock Filling Cap Genuine 28891040 2.889-104.0
Karcher Steam Cleaner Pressure Safety Lock Filling Cap Maintenance Closure Valve
Karcher Steam Cleaner Pressure Safety Lock Screw Bolt Filling Cap
Karcher Safety Valve 4.580-801.3 - Genuine Karcher Part
