1SPECIFICATIONS: Including 3pcs lamp holders, small tee design for easy connection and hanging, sufficient quantity for easy use and replacement. 2E27 INTERFACE: The ceramic lamp holder has E27 interface, standard size, which is easy to install without falling off, with stable performance. 3ALUMINUM SHELL: The shell is made of die casting aluminum, treated by high temperature electrostatic spraying, corrosion and oxidation resistant. 4WATERPROOF RING: With built in waterproof rubber ring, the heating lamp holder is waterproof and melting resistant, greatly prolongs the service life. 5MAIN PURPOSE: Can be used to control the brightness of the insulation bulb and adjust the temperature, which is convenient and practical.