If you've got a Big Mike Warehouseman, you're used to sucking up very fine dusts from floors that have been ground up by your forklifts' wheels.
Fine dusts are great for building up quickly in your filters and the performance of your Big Mike can drop.
The Extra Large Filter Kit gives you a much greater surface area over which to filter out fine dusts.
You can clean for longer before the filters need shaking out and performance starts to drop.
Also, if you're cleaning up heavy waste, the Extra Large Filter can help stop your Big Brute getting too full to empty it safely.