this invention relates to the field of multiple layer plastic extrusion , and more particularly to assemblies in which thin or micro - layers of polymer material are formed which polymer material may be from two or more individual extruders , and delivered to a multilayer combining adapter in association with an extruder die or other utilizations . the combining adapter of this invention is referred to herein as a flow velocity profiler and includes a cartridge assembly body that is formed with individual cavities that receive on of plurality of . changing individual inserts is less time intensive that changing an entire body as required in prior art .