The Digi-Wave 400 system allows users to listen and talk to one another simultaneously and wirelessly for various group scenarios. A standard system requires at least one transceiver and one receiver. The DLR400RCH receiver has crystal-clear digital sound quality and supports unlimited listeners. Using the frequency-hopping algorithm it avoids interference and is a very secure method of communication. Use with headsets microphones (sold separately) or built-in speaker. Combinations of one or more DLT’s and DLR’s can be used to facilitate different events depending on what needs to be spoken and what needs to be heard. Typical scenarios include: Guided Tours - One or more tour guides (2-way) with audience participation (2-way) or w/out audience participation (1-way) Language Interpretation - one or more interpreted languages transmitted to audience (1-way) Intercom - with up to six people able to speak simultaneously and even more listening Hearing Assistance - featuring boosted audio for improved comprehension Features Crystal-clear digital sound quality Rechargeable batteries will work up to 32 hours per charge. (sold separately) Charge time - 5 hrs. Add any number of receivers to a system to accommodate all different group sizes. Easy pairing and easy group join (for guest units) Typical range 325 feet 3.5 mm TRRS headphone jack. Use with earphones headphones or neckloop (sold separately) Backward compatibility with Digi-Wave DLT300 Portable -no base station or rack-mounted components required 2-years warranty on parts and labor (90-days on accessories); 6 months on internal battery.