24v 5w bulb with an E12 small screw cap. This quite uncommon type of bulb is used in some old Christmas decorations. The larger thread E14 lamps are much more common. With Christmas decorations, especially older ones the screw thread on the bulb could be an E5, E10, E12, E14, E17. Before ordering, check the following details: Voltage of the bulb - commonly 24v or 240v (mains), Wattage of the bulb - often somewhere between 3w and 15w, Screw thread size - measure carefully, 2mm makes all the difference between E12 and E14!.
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