When this turned up,packaging was damaged,so didnt know if the heater was damaged or not,couldnt set it up on my tank staight away,due to ill health.Two weeks later got it set up,and works great,keeps constant heat thoughout the tank,and works well,must be fitted to the return pipe/hose on canister filters,would highly recommed it,if you dont like to see your heater in tank,then this is the external heater for you.👍
(HYDOR 300W 16MM IN LINE AQUARIUM HEATER)
Haven't actually used this new one yet, but already have one up and running for the last 3yrs with no problems. This one will be on my second large eheim filter as a back up if and when the old one should fails (I won't hold my breath as they are so reliable) .