of opposed slots 103 slots 103 serve as means for mounting resiliently compressible friction members 120 on upper stud member 100 projecting laterally from the center of web 101 are a pair of spaced vertical walls 104 which define a third slot or channel 105 slot 105 serves to receive screw 70 which is used to secure upper stud member 100 against movement with respect to lower stud member 62 fig6 each leg 102 of telescoping upper member 100 terminates in an enlarged bead 102a beads 102a provide some tolerance latitude in that if upper member 100 is extruded so as to be slightly oversized some of the surface material will scrape off beads 102a in engaging the interior of lower stud member 62 so that a slidable relationship can still be achieved the exterior surfaces of legs 102 themselves and the ends of web 101 itself do not directly engage the interior surfaces of lower stud member 62 threaded fastening member 70 comprises a self tapping screw of approximately three quarters of an inch it is received in a suitable aperture near the top of lower stud member 62 and its threads dig into the interior surfaces of lateral walls 104 to positively secure upper stud member 100 against movement with respect to lower stud member 62 when such secureness is desired resiliently compressible members 120 are preferably short lengths of conventional trim material usually referred to in the art as 34 t molding 34 t molding is typically extruded of a polymeric material such as polyvinyl chloride each resiliently compressible member.