Juno Lighting T807WH Trac-Master Slants Low Voltage MR16 Round Back Mesh Lamp Holder, White Height: 5-1/2-Inch, Width: 4-1/4-Inch Ceramic socket uses one 12-Volt, 20-75-Watt MR16 bi-pin lamp that is dimmable using dimmer specifically designed for use with electronic transformers Copper alloy contacts provide precise spring action - no arcing, will not take a set and pulls to up position for two-circuit application Polycarbonate transformer housing holds die-formed metal lamp housing and metal mesh back 90-Degree vertical aiming capability and 358-Degree rotation