side view of the lamp base 12 in this embodiment as shown in the exploded view of fig2 a the rough surfaces of the strap 21 shall retain the lamp bulb 11 and the lamp holder 13 on both sides thereof and a top rim 216 which is formed at the free end of a strap 21 can fix the lamp base 12 at a right position the top rim 216 is also used as means to pull out the base 12 from the lamp holder 13 in fig2 a 22b and 22c yet another embodiment is shown with four insert straps 21 formed on the top rim of a lamp base 12 which is substantially half the length of a normal lamp base 12 described above the inserting straps 21 have raised ribs and or dots at least on one of the surfaces of these straps 21 and a grooved folding line 215 is formed at one end under or on the strap 21 close to the lamp base 12 for facilitating the upward bending of straps 21 it is shown in the enlarged view of fig2 a during assemblage the straps 21 are bent upward to form a cylindrical shape with their free ends to form a top rim 216 the straps 21 can retain tightly the lamp bulb 11 and the lamp holder 13 between the side surfaces tightly by friction and the top rim 216 can stop the lamp base 12 at a right position when.