A zf2741 outdoor AP (and zf2942 indoor AP) has one 2.4GHz 802.11b/g radio/antenna. It does not have 802.11n capability, and does not have a 5GHz radio.
You can configure a 2942/2741 to use 'ofdm-only' which eliminates CCK and
802.11b only clients, but still will only get 6, 9, 12, 18, 24, 36, 48, 54mbps max
throughput.