The GE GXRTDR inline water filter may also be used as a replacement water filter for the GE GXRTQ Water Filter System and its replacement water filter, the GXRTQR. The GXRTDR water filter uses no fittings to install, the water line pushes in each side and provides a water tight seal. You will not use the fittings that you originally used with the GXRTQR this filter does not have any fittings. Easy for the do it yourself minded person.