The BP-900 from Anchor Audio/Portacom is a high-quality wireless beltpack designed for full-duplex communication. Up to four users may communicate in duplex mode, while an unlimited number of users can listen in. A system of beltpacks can be divided into four separate groups that operate in the 944-952MHz range, so there's no need for a base station.
The ergonomic beltpack has an XLR headset jack that can accommodate single or dual-ear headsets (sold separately). The heavy duty antenna provides clear communication at distances of up to 250' for duplex mode and 2500' in simplex mode. Controls for group selection, headset volume control, and mic sensitivity control are provided. A push-to-talk button is available, although you can choose voice-activated communication as well.
The beltpack uses four standard AA batteries, and four rechargeable NiMH batteries are included. In continuous transmit mode, the beltpack can operate for approximately 3.5 hours, while it can operate for approximately 7.5 hours in receive-only mode. If desired, a gang charger is available separately that can charge up to four beltpacks simultaneously.