Culligan SW-5 Water Filter Housing Wrench Use the SW-5 wrench only for twisting off water filter housing sumps. Do NOT use the SW-5 housing wrench to secure the water filter canister to the water filter lid, damage may incur to o-ring. The SW-5 wrench makes changing water filters easy. The SW-5 spanner wrench can be used with many under sink housings. The SW-5 wrench is approximately 3.5-Inch Wide. (Note: Width is slightly less at the notches.)