I am wondering everyone's thoughts on these double element heaters? It looks like the controller adjusts the wattage to maintain the set temp. I do like the compact size, especially considering this one is 500 watts. This one is made by Hygger.
https://www.hygger-online.com/product/submersible-double-quartz-heater/?ref=fish
https://www.hygger-online.com/product/submersible-double-quartz-heater/?ref=fish


