32 in order to facilitate the snap fit between the inserts 30 and the frame 20 a flange 34 extends from the upper periphery of the insert 30 the insert 30 fits within the opening 21 so that the underside 34 a of the flange 34 abuts the face 20 a of the frame and the prongs 33 snap behind the peripheral flaps 22 of the openings 21 fig2 b shows the underside of a different embodiment of the insert 130 usable with the frame 20 in this embodiment the branches 132 and prongs 133 are substantially the same as those discussed with the previous embodiment the underside 134 a of the flange 134 abuts the face of the frame just as in the previous embodiment the flange 134 is shaped slightly differently however having side cut out 134 a on each side the cut outs 134 a are provided directly above the prongs 133 imply to permit the insert 130 to be readily two part press molded as will be appreciated by those skilled in the art as shown in this view the pockets can also be provided with underside features 135 shaped to hold a component in a pocket of a tray below when the trays 10 are stacked one upon another this feature is also well known in the art in the illustrated embodiments the branches depend from all four sides of the insert however it would be acceptable to provide branches on fewer sides so long as a reliable snap fit is obtained for example the branches can be provided on two opposing sides.