This link may generate a warning but should be possible to download in the event it is required. :::
Please see below link for BraileSense U2 version 9.0 firmware link.
http://hims-product.s3.amazonaws.com/BrailleSense/Braille_Sense_U2_UK_V900_191217.zip
This link may generate a warning but should be possible to download in the event it is required. :::