Savox Hardline Rescue Kit 1 with Power Talk Box is our best selling technical rescue confined space kit. It is designed for: Confined space rescue Collapse rescue Urban search and rescue High angle rescue Trench rescue It enables simultaneous, two-way voice communications between the rescuers and the victim. Rescuers use it where traditional radios fail or when hands-free, secured communications are required. Attendants communicate with entrants and monitor their safety. The backup team can also listen to the entrants’ rescue and be ready to relieve them. The power talk box is a portable intercom system that is dropped down the hole before entry to determine a victim’s condition. The whole system and accessories are waterproof. The rugged molded fiberglass enclosures, all external knobs, and signal cables with their military connectors are impervious to a wide range of acids, alkalis, fuels, and other corrosive chemicals including Skydrol. All of the above coupled with a highest level of intrinsic safe approval is why you can trust them with your life.