Most portable 3G routers — we're thinking here of models such as NetComm's MyZone, Virgin Mobile's WiFi Modem or Internode's MiFi — have tended to the smaller side, as befits their portable nature. AximCom's MR-102N is larger. Not huge, but where the other competitors are around the size of half a pack of playing cards, the AximCom is more like two thirds of a Nintendo DS. It's still portable, but at 10x7.5x2cm, it also won't easily fit into a shirt pocket the way most other portable routers will. Add in the fact that if you're using it in a totally wireless fashion with a 3G USB modem or connected smartphone and you're adding another few centimetres to its overall size, making it entirely impractical for carrying about your person unless you're the wearer of very large pants indeed.
The MR-102N is a portable 802.11n-capable router with connections for 3G USB modems or tethering-ready smartphones and 10/100 Ethernet. It's not full-strength 300Mbps 802.11n, however, as it's only rated for up to 150Mbps performance.