The ENS500EXT comes with a pair of detachable 5dBi omni-directional 2.4GHz MIMO antennas. The antenna connectors on the ENS500EXT are RP-SMA (female). This means that the antennas should have RP-SMA (male) connectors or adapters.
Figure 1: ENS500EXT RP-SMA(female) antenna connectors