The bunnyPAPR is free for noncommercial use with 3D print and assembly instructions.
bunnyPAPR.org is a group of people trying to scale, deploy, and popularize the design.
Bunny Science PAPR is the design, and Dr Kuo is the inventor.
Rough pricing (at scale) is below.
A few warnings
Though dozens of people have built their own, it's not always easy.
Typical build time is two days spread out over two weekends. Don't expect to build it in 2 hours.
One day to read the instructions and to order parts.
Then, wait to get parts.
Then one day to assemble.
It's not easy to get the parts. They mostly are not on Amazon.
In particular, the viral filters are hard to buy in small quantities, but you can find them on Ebay.
Do not make modifications unless you know what you are doing and thoroughly test it.
READ THE COMPLETE INSTRUCTIONS ON
Recommended First Prints:
(EASY) Print and assemble a flutter valve. ~45 minute print time. (filename is bag_flutter_valve_deflector-free_r1.stl or a more recent version)
(HARD) Print the halo loop. ~3 hour print time. (filename is Loop_Tilted_Long_Ears_r1.st or a more recent version)
When you complete your first print, please post a picture on our Discord chat server to interact with other 3D printers or ask for help about 3D printing.