Selector switch of the Datex-Ohmeda Aestiva 5 machine Selector switch of the Datex-Ohmeda Aestiva 5 machine. In addition to switching from the reservoir bag to the ventilator, it also turns on the ventilator. Also note the adjustable pressure-limiting valve and airway pressure gauge. Source: Circle Circuit, Anesthesia Equipment Simplified Citation: Rose G, McLarney J. Anesthesia Equipment Simplified; 2014 Available at: https://accessanesthesiology.mhmedical.com/DownloadImage.aspx?image=/data/books/871/rose001_fig_07-05.gif&sec=51860588&BookID=871&ChapterSecID=51860171&imagename= Accessed: October 09, 2017 Copyright © 2017 McGraw-Hill Education. All rights reserved