Glass (Quartz) Tube for 6W UV Ultraviolet Light Bulb This glass tube is a replacement tube for 6W UV water sterilization system. It is made of high quality quartz that can sustain higher water pressure than regular glass. It is used to isolate the UV light bulb ( eBay item #324524109951) from the water. The light bulb itself is not water proof and can’t touch water at any time. This item is the glass tube only. The tube is open on one end and closed on the other end. It does not include the UV light bulb, which can be found through eBay item #324524109951. Tube size: 8.5″ x 7/8″