Had problems with big pieces of coal blocking the hose in Kaercher AD4 ash vacuum, this simple add on prevents bigger pieces of coal going throught and blocking the hose. All you need to do is remove pieces from this nozzle by hand when they get stuck and try to break those into smaller pieces by hand. Reduced my hose blockages dramatically.

Do not use with hot ash/coal and print with ABS or something that withstands higher temperatures to make sure it wont melt right away.