ADAPTOR FOR 3M RESPIRATOR

thingiverse

This is the latest design that's been optimized: a) To maximize comfort while breathing compared to many other adapters. b) To minimize wind noise experienced in other adapters. c) Spiral blades are used to avoid direct exposure of the internal chamber to the ambient environment. A surgical mask or HEPA material can be cut into a 54mm diameter circle, though you may also cut the filter material into a 60x60mm square (or slightly bigger for easier installation). Hong Kongers (March 29, 2020)