It's very helpful to have a lid from time to time. I use mine to slow evaporation when I go on vacation. They are hard to come by in my experience so grab one when you can. Or just go to a glass company and have one made, but it will likely cost as much as this one or maybe more.
I ordered it for UNS 60A (all-in-one version) - my main purpose was for blocking evaporation. It is covering the tank (not the filter) and is well designed to fit perfectly with just a minimal extra space (CO2 tubing max). This is exactly what I was expecting so the tank is optimally covered, there is no need for space for big pipes in this version of the tank. Glass is same quality/look than the tank itself - with UNS logo - making a consistent set, packaging was perfect. Even if obvious, let's remind that glass is transparent :-) so there will be condensation under the glass that will be visible. To be aware that it is for a tank positioned accordingly, water surface higher than your eyes. Other possibility being to put it on the tank only when nobody's home for several days. I'm very happy, it will nicely save me the daily RO/DI refilling at reasonable cost!
Bought the 30C lid for my UNS 30C rimless tank. Lid fits perfectly with acrylic clips (was provided with the 25C clips but was told it would work fine with the 30C). The 30C lid provides about 1 1/2 inches in the back to put filters/ run wires for equipment. I use the space to run the wire for my heater and also as an area where some of my hardscape(wood) can pop out and be emersed.
I used this on a crabaqua tank with similar dimensions to the ada one. It didn’t fit perfectly but a clear piece of vinyl covers the gap and allows me to customize where I have my lily pipes. It shipped faster than expected and came wrapped in a ton of bubble wrap so almost no chance of it breaking in route.