Features network tester: consists of a tone generator and a probe method: use the tone generator and the probe to determine where a cable is going and whether or not (and where) the cable is interrupted signal viewing in 3 modes: lamp (L), speaker (SP) or both (S&L) tone generator output (square waveform): single (900Hz) or dual (900 - 1000Hz) comes with: soft carrying bag Specifications tone generator: working voltage: DC 9V ±15% working current: 10mA (intermittent tone) / 20mA (continuous tone) output wave form: square wave signals ±10Vpp single audio frequency: ± 900Hz dual audio frequency: ± 900Hz - 1000Hz dimensions: 4.5" x 2.4" x 1.1"x weight: ± 130g probe: working voltage: DC 9V ±15% working current: 25mA (L) / 80mA (max. SP volume) / 100mA (max S&L volume) max. reception sensitivity: > 30mV maximum output volume: ±120dB dimensions: 8.1" x 1.6" x 1.5" weight: ±80g