We just ordered the Eartec 24 g system, which allows the climber ("master radio") and one other person (one of any number of remote radios) to talk simultaneously, with all the others able to listen in. The remote radios can switch off between themselves to be the one who can transmit, but they'll have to signal each other to switch. No base station, so a lot less expensive. After a year of trying to get Peltor and a local vendor to fix the defective headsets we previously used (and they broke after just one use), I decided to move on to a better system.