The ProStar lid is made of a polycarbonate (Lexan) material with a clear mesh. The 150,200, and 230 come as a two part lid to make removal and maintenance easy. The lids come with 3 different size openings for light brackets. These cutouts can be removed though the use of a hand held hack saw. The bracket dimension are based on the most popular light brackets on the market. ProClear does not guarantee that these cutouts will fit every light in the market so please be sure to review the dimensions before purchasing. There are triangular cut outs on the corners of the lids for feeding. Light bracket dimensions are shown below. (evaporation covers have been discontinued ).