4 x 8 Watt T5 UV Bulbs for 8W / 16W Fly KillersSuitable for most 8W / 16W Insect Killers / Bug Zappers including EazyZap, Flymatic, Vermatic, Prozap, Xterminate, PlusZap & many othersPeak UV Wavelength of 368nm - Optimal for Insect / Fly KillersLength: 290mm (Approx. 12 Inches). Diameter: 16mmBefore purchasing lamps, please make sure that your fly exterminator matches the wattage of our product specifications; It is recommended to replace the starter every time the lamp is replaced, and Parts using electronic ballasts do not need to be operated; When replacing, shaking the bulb to make a clicking sound is normal and does not affect the use effectWhen shopping, please pay attention to the size and dimensions of the product to ensure that it meets your needs. In the title and , we have provided detailed information about the product, including its features and specificationsWe want you to be completely satisfied with your purchase, so if you have any questions or concerns, please don''t hesitate to contact us. We are here to help and will do our best to assist you.Thank you for choosing our product. We hope you enjoy it!