... , theftproof, mothproof, rainproof, low noise, high efficiency. One ventilation system includes 2 unit, air intake unit and air outtake ... or automatic. If want to control the work of ventilation system automatically based on temperature, a HW11A or other ... tapping screw or rivet.(6) Check the installation.About out companyHANGZHOU XINJIAN ELECTRINOC CO., LTD. is a ISO9001 certified manufacturer, and ...