PULACO 25W Mini Aquarium Heater with External Controller & LED Temperature Display, Adjustable Submersible Betta Fish Tank Thermostat

How long is the cord? What is the length (ideally in inches) from the plug end to the controller & the controller to the heater. Also overall length?

Will this heat up a 5 gallon tank

Does this fit round tanks?

I purchased this heater and it will not stick to my aquarium. I have done all i know to do...one cup sticks the other will not. Can i get another