Ordinary radio communications pose difficulty in many confined spaces because the space's confining walls block radio signals. The attendant always has a free channel to check the entrants or provide warnings. The entire system is listed as Intrinsically Safe by Underwriters Laboratories. Inside the confined space, the entrants are untethered, free to move about in comfort and secure in the knowledge that they communicate with the attendant continuously.
Work goes faster when well coordinated workers can report status, ask for tools, etc.
Hard hat brackets mount on a Bullard style, slotted hard hat. The conversion is reversible. The Earmark hard hat includes ratchet suspension. Not only won't you have to worry about tripping over wires, you won't have to listen to anybody's telephone conversation either. Both systems, Headsets and Belt-Paks, available in two man Duplex and multiman Simplex arrangements.