Case is good for led cup, lamp with 50mm diameter. Material: AluminumVoltage: 12V or 110-240VBase: MR16,E27,GU10 (selecting 1 type)Diameter: 78mm * 22.5mmInner dia.: 54mmIt is good for led cup, lamp within 52mm diameter. For more products on case series, please contact us. LED aluminium holder