More durable than what others said. I haven鈥檛 had any issues with leaks or breaking. It Doesn鈥檛 make much of a difference temp wise. I think the description was quite 鈥済enerous鈥 when they said how much it would heat. I have purchased only 1, and maybe with more than one it will heat better. I have a 15ft wide 4ft deep pool. It stays at 21 degrees. Doesn鈥檛 go more than that. This is with the heater.