This wrench is used to loosen the vertical canisters that hold the pre-filters.Sometime people loose the wrenches that come with the purchase of their Aquasafe Home R.O. and Aquarium Systems. You do not necessarily need to order new wrenches from us. An oil wrench that you would use to take the oil filter off your can will work just fine. If you do not have a oil wrench or something very similar, then we suggest you order a new wrench.
