10kHz-1GHz. 3V/m to 300V/m. It is NiCad powered with approximately 7 hours running time. Maximum field reading is 300V/m. It is fibre optically connected to the HI-4400 mainframe with the ability to transmit 16 data buffers per second. The response time of the head is 75 milliseconds to read 90% of full RF level. Mechanically, the head is formed by a 57mm cube with three orthogonal monopoles protected by plastic domes. Weight: 0.4kg with a ¼ x 20 tapped mounting hole in base.