1. 4 independent shelters, all made of 316 material; 2. Internal effective size: Long x high x deep /420x350x370mm; 3. Each shelter has a vacuum resistance of 0.1Mpa and an independent vacuum gauge; 4. Each shelter is equipped with independent vacuum pumping and inert gas filling connectors, and the control mode is manual control; Optional vacuum pump adapter and common inert gas adapter; 5. Each shelter is equipped with visual tempered glass window for easy observation; 6. The lower bracket is equipped with 4 independent universal adjustable casters.