This screw-type lamp holder and bulb set is an indispensable resource for conducting electrical circuit experiments. It supports both series and parallel connections, making it versatile for various educational activities. Ideal for students and educators, this set provides a practical way to explore and understand electrical concepts. Features -Color:Black -Material:Plastic, copper -Size:7.50X3.50X2.60cm/2.95X1.38X1.02in -Effortless installation: the screw socket design allows for a seamless and easy installation process, Suit for users of all levels -Brightness control: the electrical circuit design offers adjustable brightness, allowing you to the lighting to suit your needs -Energy conservation: the product's circuit design is optimized for energy efficiency, helping to lower power consumption - materials: crafted from plastic and copper, this product is built to endure extended use without damage -Multipurpose: ideal for use in electronic toys, breadboard power supplies, school labs, and technical courses, this product supports a variety of projects Package list: 4 x screw lamp holder