melt flow rates between 1 and 24 preferably between 1 and 12 grams 10 minutes per astm d 1238 are especially suitable such suitable resins include both homopolymers and copolymers of bisphenol a and include branched resins such as are described in u s pat nos 3 544 514 and 4 185 009 these resins typically can sustain a strain before substantial plastic deformation occurs of about 8 and have a tensile modulus of about 3 3 u00d7 10 5 psi these materials are available in transparent form so that various indicia can readily be inserted into the hollow lens portion they can also be obtained in a variety of opaque and translucent colors additionally they can be extruded and or coextruded to give surfaces with multicolor patterns those of these polycarbonates which have a notched izod impact strength of at least 5 ft lb in a 1 8 34 specimen and which can sustain at least about a 5 elastic strain are especially preferred other well known thermoplastic engineering resins may also be suitable the polyamide resins based on aliphatic dicarboxylic acids and aliphatic amines or on caprolactam are among these materials of particular interest are the nylon 6 and nylon 66 resins also of interest are the thermoplastic polyesters such as the polyalkylene terephthalates described in u s pat 3 516 957 blends of these resins with polycarbonate such as described in u s pat 3 218 372 and impact modified versions of these resins such as described in u s pat no 4 297 233 the particular end use to which the elongated article is put may dictate further material.