The housing spanner is a tool to assist with the opening of the filter cartridge housing. As water fills the filter housing pressure builds up inside the housing, this fact plus age can make the housing difficult to open by hand. The housing spanner allows an individual to get a better grip on the housing and so makes it easier to open the housing.
Please keep in mind that the housing spanner is purely for opening the housing, do not use the spanner to reseal the housing as it can result in "Over tightening" which can damage the housing's thread leading to leakage and making it very difficult to reopen.
There are two types of housing spanners avaliable:
Big Blue Housing Spanners:
These spanners are designed to open both the 10 Inch and 20 Inch Big Blue housings.
Standard Housing Spanners:
These spanners are designed to open both the 10 Inch and 20 Inch standard blue housings, as well as the bottom housing on an RO or Nanofiltration system.