Radios just don't work in confined spaces. Cell phones? If your local carrier is like mine, it isn't reliable above ground, much less down below, or in heavy metal environments. Yelling? Please. If yelling worked, you wouldn't be reading this. Tugging on a rope or banging on a pipe are also terrible ways to pass information back and forth, especially in an emergency. The only viable answer is a hardline communication system. And nobody provides a better product than Con-Space Communications. Con-Space equipment is designed with the KISS system firmly in mind (Keep It Simple, Stupid). Connections between the various components use durable twist locks that are military-grade with gold-plated contacts and O-rings at each opening. This simple, thorough construction guarantees that you can drag this unit through the mud, get it wet, pull it around corners, and it's going to keep working. Con-Space systems like the Con-Space General Industry Kit provides communication 100% of the time. The throat mic is the best on the market, ensuring clear communication even in the noisiest environments. It takes its sound directly from the vibration of the vocal chords, so it's remarkably understandable, even in the loudest locations you can think of. The CSI-1100 Mini Modular Base unit powers the system for up to 200 continuous hours of use with 4 regular AA batteries, so it's a unit that doesn't need to be connected to an outside power source. There are no extra power cords to trip over or jumble up the work site. The base unit is made to handle two workers. One interesting thing about this system is how easily it can be expanded by attaching the optional splitters. More interesting is the fact that sound quality will not diminish no matter how many additional users or how much extra cable is added. Another popular upgrade for the system is the CSI-2131 Power Talk Box. This simple, powerful box allows for hands-free, two-way communication between both sides of the line. A durable fiberglass housing protects state-of-the-art electronics - a high-output speaker, and a microphone that picks up even subtle sounds. And of course this unit is completely waterproof. The cable is sheathed in triple Santoprene thermoplastic which has a longer life and greater durability than rope cables. The tensile strength of the cables is 164 lbs. and the coating is resistant to a wide range of solvents, oils, and chemicals. They also feature strain relief and snap hooks to keep the connections together, and make handling the cable easier. A speaker harness holds the throat mic ear speaker in place, and fits comfortably under a hardhat or other personal protective equipment. Workers can complete whatever kind of physical work their trip into a confined space requires while staying connected to the other members of their team. Workers on the other end of the line can keep in touch using the Con-Space Headset which is also water resistant, but is larger and provides better hearing for the controller or outside attendant. If you need your confined space entry team to communicate, don't rely on hand signals ("This means there is no air") or banging on pipes to get your message across. Con-Space Communications systems help get your workers back safe every time.