About this item Strong inner core: Main engine adopts oil-free lubricating piston pump, so that the environment is not polluted by oil mist, effectively extend working time Pressure regulation:The negative pressure is 0.02MPa-0.08MPa. In the process of using this product, we should pay close attention to the reaction of the user and adjust the negative pressure that makes him most comfortable at any time Large capacity: 1000 ml large capacity water tank, removable design, easy to clean, noise less than 70 db Installation: We have installation instructions, it only takes 2-3 minutes to install, one click open, easy to get started