Saves time and eliminates the changing of clothes on entering or leaving a cleanroom. Keeps room contamination at a low level. No air passage through the communicator. Neoprene seals holds room air pressure. No wires, moving parts, or maintenance requirements. White Styrene frame with transparent mylar "S" diaphragms and clear protective grille on both sides allow each party to see and talk to the other even in solid wall. No batteries or electrical hookup is required.