Retrofit led lamp, method for making the same, and retrofit multi led lamp set

PURPOSE: A retrofit LED lamp, a manufacturing method thereof, and a retrofeet multi LED lamp structure thereof are provided to improve directivity and the range of illumination by using an optical convex lens. CONSTITUTION: A plurality of heat radiation fins are formed in the outer peripheral surface of a heat-sink(10). A convex lens(30) is made of a transparent acrylic material. The convex lens is installed inside the fitting end of the heat-sink. A gasket ring(20) is made of a silicon rubber material. The gasket ring is inserted between the hitch bed of the fitting end of the heat-sink and the protrusion end of the convex lens. A plurality of LED modules are installed on a PCB(40). A shaft(50) includes a first cylindrical body part and a second cylindrical body part.