This new UVC from the new Pond Kraft range has an ' Easy Open' casing that makes it simple to change the bulb. It uses a modern single ended bulb & comes with inlet & outlet hosetails to fit 20-40mm (3/4 to 1 1/2"). Inspection glass lets you check if the bulb is working. 2 year guarantee. To read more about the Pond Kraft UVC including how to change the bulbs please click here."