Integral radio system for protective helmets - has radio receivers and transmitter/receivers in helmet

摘要

In the transmission/receiver version, the transmitter/receiver is installed in a removable blister at the back of the helm et. Power is provided by a battery and tuning and volume controls protrude from the bottom of the blister. Earpieces and microphone are connected to the transmitter/receiver by internal cables respectively. Other receiver configurations, including some fitted in removable earpieces are described.