>>15217308Yes their purpose is to block all the slots exept the first one so only one type of item can get in and out because of how hoppers work and how redstone is set up. As i said, you can rename the filter item to literally anything other than it's actual name, or not rename it at all, but if for example you use unrenamed cobblestone as filter and somehow more cobblestone gets into the system it will be able to pass through the filter and potentially break it because it can stack with the cobble that you used as filter. But if you rename it will only be able to stack with more of that renamed item, and i guess everyone just names it "filter" for consistency
