Mermaid baking/roasting tins are really superb, we have several now. They have a great, solid-feeling quality. They do not warp in the oven, and they are really easy to clean. Whether I have gently cooked something or cremated it beyond recognition, a simple soak and then clean with a sponge or nylon scourer (which does not mark them at all) brings them back like new. I did accidentally put one in the dishwasher once, and thought I had ruined it, the surface looked terrible. But a few good oilings before the next few uses brought it back, and now you would never know. Hand washing only!
Well worth the money, should last for years and years. Our oldest roasting tin is about 7 years old now, and despite at least twice weekly use, still looks almost brand new.
The tins in this set are smaller, approx. 17cm x 27cm, the flat one being a little bit longer than that due to the handles.