Review on Eheim Jager Aquarium Thermostat Heater: Optimal Temperature Control for Your Aquatic Environment by Jasmine Jimenez

This evaluation is only about the physical aspects of the heater. Since the seller's product description does not have clear dimensions, I can confirm that the 50w heater is 9.5 inches. below (total size including dial). It's too big to fit vertically in my aquarium. It needs to be fully submersible, but I don't want to turn it horizontally because I want the temperature dial to be accessible without putting my hand in the water. The bottom of the heater is open glass with no protective cover, which is annoying that it's more prone to breakage. I think it should include a rubber stopper for the bottom. The power cord is thick and stiff and only about 6 feet long, which may not be enough for all applications and doesn't allow for much more for a safety loop. I'm going back because it's too big for my tank so I didn't get a chance to use or check the heater.