Use trimmed surgical glove as a membrane or other suitable elastomer, 3x M4 bolts, tap/thread the main body. Pneumatic fitting on top. First revision, been demo'd briefly. Please email me for requests in changes for this design, for different sized ports or fittings etc. My email is charlton.christopher@gmail.com. I have attached a ventilator diagram to this design pack, see the PEEP valve on the right hand side. This version has some more adjustments based off a 3D print and some very brief testing (23rd March 2020). I will be uploading a one way (check valve) very soon so keep an eye on my other uploads.