So I had the good fortune today to get a free 60 gallon breeder tank (48in x 18in x 17ish in); unfortunately it didn’t come with a lid. What are your favorite screen lid options for a tank that size?
I’m hoping to eventually make it into a bio active setup for my garter snakes; they’re way too small for it now so I’ve got plenty of time, but I’d like to start planning for the future and keeping an eye out for deals. 
I hate top opening enclosures so I either convert it to a front opening terrarium by removing all the trim, silicone, and cutting the glass, or more easily just turning it on it’s side and using acrylic or glass to make a substrate lip and doors on what was originally the top. If I need screening for lights I make it out of aluminum window screen repair kits or out of PVC corner trim and metal screening stapled and siliconed in place. You can also buy commercially available ones, I dont really have a favorite since I hate having to climb in enclosures from the top lol
Front opening tanks are more ideal and easier to use but as far as screens you could just research 48x18 screen lid. As long as it works there shouldn’t be a difference between the products. You could also build one by taking metal (or a similar material) and bending it into a 90* angle of the length of the side, then attach the edges of the metal. Then once you have a square outline attach screen to the bottom.