These bulbs are geniune Jebao made from high quality quartz glass to help give the best possible ultra violet light emission and results.This 9w bulb is Length: 146mm excluding pins

Changing a bulb: When changing your UV bulb/lamp take care not to touch the glass section as any moisture on the glass surface could cause the bulb to crack. It is recommended that PLS bulbs/lamps are replaced every 6 to 12 months. We recommend changing at the start of the spring summer season to ensure optimum usage. Buy with Confidence: Top Quality Genuine Jebao Quartz Glass Branded Stamped Marked Product and Test Passed. This product has passed the test of CE and ROHS. Product Dimensions and Technical data: Total Length 105mm (4 inches approx.) - Width 30mm – Glass section length 67mm. Power 5 watts – Twin filament with 2 pins. Jebao PL-S 9w Replacement Bulb Lamp: Suitable for Pond Pressure and Gravity Filters plus UV Clarifiers or Sterilisers - UV bulb will fit all major manufacturers.