The Paralinx Array comes with a 12dBi attenuator. This is required to comply with regulating bodies in certain jurisdictions. The use of this part is at your discretion. Please check with local authorities to know if you need to step the antenna from 19dBi to 2dBi using this device.
Installing the Attenuator is easy. Connect it to the 2nd connection on the left, from the bottom as shown in the picture below. Then the antenna cable can be screwed to the attenuator itself. This cable is to be installed on the uplink channel on the Tomahawk receiver. The uplink channel is the RP-SMA connector that is second from the left on the side of the receiver that the LEDs can be seen from.