Question about Wittenberg Antennen LAT 56 Duo

The Wittenberg antennas here e.g. "Wittenberg LAT 56 Duo" are clearly not handheld radio accessories (as stated in the heading above - they are rather accessories for e.g. G5, LTE router etc.). The remark also applies to other antennas. If we were talking about increasing mobile radio ranges, we could just about accept this...