Everpure systems include a .5 GPM flow restrictor fitting that should be installed in the outlet port of the head. The fitting limits the flow of water that can go through the filter to .5 GPM.
To increase the flow to 1 GPM to match the flow rate of the MAF Cartridge, the .5 GPM fitting must be replaced with a 1 GPM fitting. The MAF cartridge will work with the .5 GPM flow restrictor, but the flow will be limited to .5 GPM. It is only necessary to replace this fitting if you desire an increase in your flow rate.
It is possible that the flow restrictor may be installed on the inlet port, however this is not recommended. If upon removing the fitting from the outlet, if it is not found to have a flow restrictor in the fitting (usually stainless steel), remove the inlet fitting and see if the flow restrictor was installed on the inlet side.
It is recommended that the flow restrictor be installed on the outlet port to prevent the small opening from becoming clogged with sediment from the untreated water.