General default MR16 connector is gu5.3 lamp holder, insert two pins. Current halogen MR16 socket, GU10 lamp holder, whether or MR16 connector, can be made high and low pressure, because it has a relationship with the lamps inside the drive. MR16 bulbs have two pin connectors. While the GU10's use a push and twist method of connecting to the socket. the MR16 simply push in place with metal clips also gripping the edge of the bin base. They use a separate power supply , either an old type transformer or a newer switch mode to convert 250v AC mains to 12vDC.