The flexible foam face mask can be removed at any time, thanks to squishy pegs that pop out of the HMD with a simple tug.
This is especially nice if you suffer from SFS (Sweaty Face Syndrome).
We also take the opportunity to snag the HDK's circular peepers. While they may look reminiscent of those in ye olde Oculus, rather than the Fresnel lenses we've been seeing in devices lately, these are actually dual-element lenses, with lower chromatic aberration and no Fresnel "God rays." They are related to this earlier (HDK pre-1.3) design.