IMPROVEMENTS IN CLOSURES FOR CLOSING RECEPTACLES

摘要

A closure (1) for a receptacle which can be used for promotional purposes in an operating system by distinguishing certain closures from others of similar appearances. The closure is manufactured with an optical tracer (5) incorporated into at least some part of the closure. The optical tracer (5) emits light at a predetermined wavelength to distinguish it from other closures not having the optical tracer.