OEM's are prevented, by FCC Rules in the US, from using "Commonly Available" RF Connectors on any Part 15 (802.11x) Devices. This is to keep folks from unknowingly violating the Part 15 Rules on Transmitted Power Density. Most ALL of the Wireless Access Points, Routers, etc, that have External Antenna Connectors will be using Reverse Polarity SMA, or Reverse Thread SMA Connectors, to be in compliance with Part 15.