The DigAlert™ 361 (D361) models of the Nautilus test telephone range offer the same essential features that every telephone technician needs as the D350 models; super high impedance monitoring of the line so as to pose as little risk as possible to parallel data services plus protection and warning of conditions such as high voltage and excess current. Plus you have DigAlert that will warn of the presence of "out-of-band" signals such as digital services such as ADSL right through to the current VDSL2 services. Add to that "loudspeaker listening" capability and you have our most popular and versatile model of telephone buttset. Plus the D361 models include "full hands-free" loud-speaking telephony.
There are also two specialist models: One which has an additional circuit to detect metering pulses at 12 kHz that are still in limited use in some markets. The other includes a DigAlert detector circuit with wider bandwidth that is required for some customers who operate VDSL with a starting frequency somewhat higher than standard (> 150 kHz). Includes 3-year warranty.