The mulch plug stops the grass from coming up the chute so it is mulched and recirculated from the deck. The grassbox goes back on to activate the sensor switch to allow the blades to switch on but won't have any grass going into that. I hope that makes sense. Thanks
My mulch attachment is a good lot shorter than yours. Am I missing something? Also I find the mulch sticks to the mulcher , so much so that I have to get under the deck to clear it .. a pain..
If the mulch attachment is too short then it is possible that it's not the correct one for the machine. If you want to email us the model number of your AL-KO machine we could check the part number of the mulch plug that fits it for you.