keyed binding lever 204 as shown in fig1 the binding lever 204 includes a knurled top section 222 a retaining ring 224 an annular rib 226 and a lower section 228 the lower section 228 in this case is oval shaped for a snug fit into the lower section 230 see fig1 of the cavity 212 the section 228 is designed to extend beyond the plane of the base 210 for cooperation with an appropriately shaped receptacle in an external structure so that the spool caddy 200 will be keyed i e positionally aligned to the external structure turning back to the spool caddy 1 of fig1 and 2 the snap plate 40 having a thickness 34 z 34 includes a centrally located cavity shaped opening 46 similar in shape to the cavity 20 of the body 10 as well as a slot 25 corresponding to the slot 24 of the body 10 the snap plate 40 functions as means for detachably retaining or holding both a plurality of processing spools such as the processing spool 80 of fig2 and the film cartridge 70 of fig6 a the snap plate 40 may be clover shaped as shown in fig1 and 2 or its shape could vary as shown by the snap.