Find other files here: https://www.thingiverse.com/groups/hackthepandemic
Register resources with MatterHackers here: https://www.matterhackers.com/covid-19
This one looks fast and cheap to run on a laser cutter. PDF and DXF files are available: Thingiverse | Mirror
This is converted from a FDM-optimized design. PDF and DXF files are available: West Virginia University | Mirror
This one is described as being approved for use in a clinical setting by the NHS. STL files are available: Thingiverse | Mirror