inject the filter to maplestory
put your mouse over an item in your inventory you want to filter -> the ID will show up in the item filter
click "copy item id"
(if you don't have the item in your inventory, search for the ID in "Items.txt" by pressing ctrl+f
and entering the item's name, then add it manually to the filter)
click "add"
tick the entry in the list
click "enable"