Califone WS-TG10 10-Person Tour Guide/Assistive Listening System System Includes One WS-T transmitter, Ten WS-R receiver, One HBM319 headband mic, Ten 3060AV headphones, Three WS-CH 4-piece beltpack rechargers, One WS-CHP Power Adapter for 4-piece, WS-CH, One WS-CS12 Case Low TX Power / High RX Sens.: > 200" *, High TX Power / Low RX Sens.: > 200" * High TX Power / High RX Sens.: > 300" * * Line-of-sight required. Range may be lower due to obstructions / interference