These light stabilized unbreakable clear poly-carbonate U. V. filtering sleeves are designed to provide protection in case of fluorescent lamp failure. In addition to containing broken glass particles and lamp chemicals, which protect personnel from injury, the Fluorescent Dimming Sleeve allows you to regulate the light output or reduce lamp glare by simply turning the sleeve with your fingertips to your desired comfort level. End caps are included. For use with F28-T5, F32-T8 & F40-T12 lamps. These sleeves are neither recommended nor guaranteed for use with high output T5 lamps.
The size was perfect, covered the hole in the ceiling just like I wanted.
Under Cabinet Light Lens 2.8125in. wide x .9375in. high (4113P-320RW)
I had this installed as an outside cover over the crawl space vent. The metal vent always rusted and looked terrible. I wanted a plastic cover that would not rust. It's been on for one hour, and looks great.