> For the complete documentation index, see [llms.txt](https://support.keyst.one/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://support.keyst.one/changelog/keystone-firmware-btc-only/b-2.0-btc-only.md).

# B-2.0 (BTC-Only)

BTC-Only firmware B-2.0 includes the updates below:

1\. Keystone now supports Casa, a key management protocol, in multi-signature wallet mode.

2\. The labeling of the firmware versions scheme has changed. M-x.x stands for "Multi-cion firmware" while B-x.x stands for "Bitcoin-only firmware".

Instructions recommended:

{% content-ref url="/pages/-MkpBGPcelERWFQflli\_" %}
[Casa](/3rd-party-wallets/bitcoin-wallets/casa.md)
{% endcontent-ref %}