No Dual Band on ASUS N66U?

I feel like I'm missing a tiny, stupid setting, but I've only got the one wireless band (2.4ghz) on my newly installed TomatoUSB Shibby 112 on an ASUS rt-n66u.

The build I installed was tomato-k26USB-1.28.RT-N5x-MIPSR2-112-Mega-VPN-64K. Anyone have any ideas?