Features: 1). The interior space is spacious without feeling oppressive, Suitable for claustrophobic users. 2) . The cabin is firm and can be decorated according to your own preferences 2) . Interphone system for two-way communication. 3) . Automatic air pressure control system, the door is sealed by pressure. 4) . Control system combines of air compressor, oxygen concentrator. 5) . security measures: With Manual safety valve and automatic safety valve,