The filter is simple to attach in the tank with suction cups. The special thing about the concept of the pickup  is that the filter canister together with its cartridge can be removed from above, while the pump unit remains in the tank. This is a very practical solution for cleaning or changing the filter      cartridge. 
The pump sucks in the water from below and carries it through the filter cartridge to the top. Here the filtered water is directed back into the tank via the rotatable outlet nozzle.

Benefits of EHEIM pickup
Smaller  internal filter for aquariums up to 60 l.
Water inlet at filter bottom
Rotatable outlet nozzle to adjust outflow direction
Filter canister with filter cartridge easy to remove from pump unit from above
Complete with filter cartridge, ready to use
Activated carbon cartridges can also be used (e.g. during aquarium  start-ups or after medication treatment)