UVBlamp : engergy efficiency . can save up to 75% energy . can work with incandescent lamp sockets. Long life : last 10000 hours. 2.0 and 5.0 and 10.0 areavailable . 13W and 20W and 26Wfor your choice. Tube Diameter: 12 mm. Smaller size, perfect for your terrarium lighting purpose. With new phosphor , no intensity below 290nm. Very hight UVB intensity . Reasonable UVI index. Very Little UVC emission at bulb surface.