Abstract: An anchor for a tubing string for use with a sucker rod pump is provided which defines a large fluid passage area for the passage of treatment fluids through the anchor. The anchor comprises a tubular body or body extensions having two vertically spaced sets of radial ports. A flow sleeve is positioned in straddling relationship across the bore of the anchor body and has its external surface recessed to provide an annular passage connecting the two sets of radial flow ports. The upper set of flow ports are connected to a tubular flow line extending to the well surface while the lower set of flow ports are connected tubular flow line extending to the production zone or to the location where corrosion, scale or other treatment becomes necessary. The flow sleeve is run into the well with a sucker rod pump on the sucker rod string and can be detachably latched to the tubing string in overlapping sealing relationship to the radial flow ports.