If you are looking for that hard-to-find replacement lens for a four foot, four tube light fixture 1800ceiling.com may be the place to start your search. I needed a special size lens and found one that fit very well at 1800ceiling.com. Their website has precise diagrams with all measurements needed to select the correct lens. I would purchase from this company again and recommend them to others. Their service was prompt and the product was well wrapped to insure there would be no breakage.