L&LD
Part of the Furniture
Asus said it is a TriBand Router
https://www.asus.com/sg/Networking/RT-AC5300/
With AiMesh since the last 2 Firmware, the second 5.0GHz Band is Hidden and used exclusively for Backhaul, whether we have Ethernet Backhaul or not.
ASUS calls it a tri-band router... two 5.0 GHz bands and one 2.4 GHz band. Three bands, three radios, no difference.
OE
Marketing and science are two different things.

I barely believe what is on the box (or online), I believe what I know and have learned along the way.
