The heater is packed nicely and in the box is the heater, suction cup mounts and an instruction manual. The heater looks well built and has a nice long (6ft) power cord. It has a temperature range from 64-93F with and accuracy of plus or minus 0.5F. The Eheim Jager aquarium heater is fully submersible and has a recalibration feature that allows to to correct the temperature setting of the aquarium heater if necessary.
The heater is easy to use first set the heater temperature, then attach the suction cup holder to the heater and suction cup it to the aquarium glass. Let the Eheim Jager aquarium heater sit in the aquarium unplugged for 15 minutes. After the 15 minutes plug in the heater and it should be set and ready to go. I like to double check the temperature setting with a good thermometer after the heater has been plug in for an hour or two.
If the temperature of the thermometer and the heater setting do not match you can follow the instructions to recalibrate it. It is pretty easy to do.
After using these new heaters for a few months I could not be happier with the results. The aquarium's temperature is stable and I have had no issues. If you are looking for a good quality easy to use heater this is one that I would recommend.