Available in 220 or 1000 ohm impedance, and in beige or black, these drivers have been optimised for speech quality applications and are used typically for switched talkback (IFB) applications. The acoustic termination is via an industry-standard snap-ring and nipple, with the electrical connection being a two-pin non-polarised plug and socket. A range of cable options is available for connection to appropriate interface/amplifier/receiver units. Whilst they are primarily intended for use with the Canford acoustic eartubes, they can also be used with Telex earmoulds, eartips and eartubes and other similar designs.