As part of the switch to LED lamps GU40 socket are very convenient as it currently not always are the appropriate LED's to the existing base. So convert to GU40, possibly as a temporary solution. The sockets are made of ceramic with 2 holes (ca, 3 mm) in addition to the openings for the lamp receptacle. Two lead wires (wire 14.5 cm) are pre-assembled, the connector at the base is not accessible, so an existing cable must be connected with terminals. Ok for me. Price / performance voices.