Finnex Digital Aquarium Heater Controller - 500W Titanium Tube for Fish Tank - Perfect for Saltwater & Freshwater Tanks, Reef Aquariums, and Aquatic Pets

First of impression: Package came well packed, upon opening I noticed that it comes in two pieces the heating element and the controller.Analysis: The heating element is nice and heavy and the cord is real thick (18 AWG). The documentation says to rest it on the bottom of the tank horizontally above the gravel as it does NOT comes with any suction for it to be affixed to the tank glass. Even though the element is very heavy I would advise to hide behind some rocks or ornaments and big fishes move with such force they tend to move it a bit.The temperature controller is not identical to what is displayed on the box. The difference is the one on the box has a replaceable fuse at the bottom between the two power cord (one for the heating element and the other for the wall) the unit in the box does not carry one and the instruction says you cannot change the fuse either.Pros:Unit work excellent (so far) I have validate the temperature using two separate thermostats and the reading are similar. The alarm works (well the low) as I set it before connecting the heating element to the controller. As I connected the heating element (after placing into the tank) the low alert kept on sounding until the tank heated above the number I set. The configuration of the temperatures were easy and the display is nice and bright. It displays in F or C which ever you prefer. I also validated that when power is lost it retains it settings by disconnecting it from the wall for a few minutes just to make sure it works. When the tank reaches to the desired temperature the heating element turns off and the red light on the controller also goes out.Cons:Instruction is all on the box so if you need to retain the instruction for configuration you will have to keep the box it comes in. (not really a con as it so simple)Other observation: I seems that the controller unit can control heating element up to 800 watts but you would have to purchase them separately (Amazon has it for $52.50)I will recommend this unit and hope that this review helps you to decide about purchasing.