Bulb for quick connector compatible with NSK,
LED Bulb
LED bulbs have the particular feature of being polarised, unlike halogen bulbs. The positive of the connector must be aligned with the positive of the bulb, and the negative of the connector with that of the bulb. There is no foolproof mechanism or reference mark to assist with this. When replacing the bulb, if it does not work, you must "turn" the bulb around so as to reverse the connections and thus match the polarities.
Data sheet