Abstract: This present invention relates to a key-ring which makes use of a photographic roll film casing, where said photographic film has already been developed, thereby avoiding the creation of waste and reducing environmental pollution. Said photographic film casing, without the corresponding photographic material therein, will be used together with the structure proposed by this present invention as a means for holding keys, commonly referred to as key-rings. Our invention incorporates, on the periphery of the insert or cylindrical rod, outer lugs which will give a similar configuration to an outer threading, and which will allow said insert to become firmly fitted and locked to the corresponding threading central hole of the photographic film casing, thereby avoiding the use of any glue or adhesive. The rod end not inserted to the casing will have three preferred forms of embodiment, such as a ring or a loop which closes on itself or on a small hole on which the outer ring is coupled.