This is the IYONIX (codename Tungsten) stable release ROM image. It can be used to test the release on your IYONIX by loading it from disc in place of an earlier flash ROM version.
You will also need the HardDisc4 image from Miscellaneous downloads for this release of RISC OS.
Softloading this image will add some time onto your boot sequence but if you do find you have problems, it is a simple matter of removing the softload from your boot sequence to revert to your original setup.