The light bulb socket is recessed, and the light bulb's threads can't reach! This is a set of 4 extension sockets that can be used in such a situation. The thread size is E26 ➟ E26, and the black plastic part extends about 3cm. Although unused, these items were stored in a warehouse without being packaged for shipment, so they feel more like slightly defective goods than brand new. Therefore, I've marked them as "Like New." ※ Instant purchase is OK. ※ No discounts are possible due to the low price. ※ No cancellations, returns, or claims, please.