Durability: The aluminum housing is more robust, with good insulation, heat resistance, and corrosion resistance. Rated voltage: 250V, rated current: 4A, heat resistance: 180C. Application: Suitable for various light fixtures, E27 lamp holders, energy-saving bulbs, etc. Also suitable for spotlights with E27 bulbs, display spotlights, etc. Caution: Due to the buckle between the lamp holder and the bulb housing, do not overtighten it before installation, as it may not open easily after tightening. Specifications: Color: Black. Dimensions: Diameter 3.9cm, Height 5.4cm, Center hole diameter 1cm, Outer prong height 2.1cm, and Outer ring diameter 5.6cm. Package includes: 4 lamp holders. Note: 1. Please allow for slight errors due to manual measurement. Please make sure you do not mind before bidding. 2. Colors may vary depending on the monitor. Hello, please pay attention to your shipping address when purchasing products. If your shipping information (such as name, street, house number, doorbell/no name email address, etc.) is incorrect, the order will not be delivered correctly.