Check the listing for details. Filter Housing Wrench Water Spanner RO 10"x2.5" Housing Durable Handle. Condition: New. Listed at 8.99 USD. Reverse Osmosis Water Filter Housing Wrench / SpannerThis Wrench turns your housings loose with ease,making the need to change your filters easier to do. Can turn Standard Slimline 10 inch housing units of regular reverse osmosis systems. For Reverse Osmosis or Water Filter Housing. Disclaimer: You should only use this wrench to unscrew your filter housings units, replace your filters, then re screw the housing units back to their threaded caps by hand. Water filter housings contain rubber water sealing o-rings. if you re screw and over tighten with the wrench, you risk the possibility of tearing or breaking the water sealing o rings, as well as damaging the filters. if you do encounter leaks: turn of your feed water supply. if your system has storage tank attached, and its own on/off faucet: turn off the tank ball valve, turn on faucet and drain excess water till the water comes to a stop. these steps are necessary to make sure your system is shut off and to relieve the pressured water in the system. Do not assume using the wrench to tighten will stop leaks if leaks occur, you need to stop and recheck your o-rings see if you properly aligned your filters.