Abstract: A fluorescent tube comprising a cylindrical glass tube having end portions, connection wires through the end portions, and a socket capping. The end portions are gas-tightly sealed and each has an annular collar and groove. The capping is made of an elastic, bendable thermoplastic material such as poly(ethylene-terephtalate). The capping comprises a frontal portion, contact pins therethrough electrically connected to the connecting wires, at least one drop of glue which dries at room temperature within a maximum of two minutes, and an annular wall extending circumferentially from and perpendicular to the frontal portion. The annular wall has at least two knobs protruding inwardly. The knobs are equally circumferentially spaced around the annular wall and at least one of them has a drop of glue on it. When the capping is fitted to the tube over the end portions, the annular wall elastically deforms and the knobs slide over the collar and snap into the groove.