I&#x27;ve seen previous mentions of it (probably on &#x2F;r&#x2F;microsoft or somesuch), though they stated 3h in &quot;tablet mode&quot; (screen only, not design mode with the screen reverted on the base)<p>edit: <a href="https:&#x2F;&#x2F;www.reddit.com&#x2F;r&#x2F;apple&#x2F;comments&#x2F;3npv7p&#x2F;microsoft_surface_book_claimed_to_be_twice_as&#x2F;" rel="nofollow">https:&#x2F;&#x2F;www.reddit.com&#x2F;r&#x2F;apple&#x2F;comments&#x2F;3npv7p&#x2F;microsoft_sur...</a>? has multiple mentions of the 3h &quot;screen only&quot; version ([e.g.](<a href="https:&#x2F;&#x2F;www.reddit.com&#x2F;r&#x2F;apple&#x2F;comments&#x2F;3npv7p&#x2F;microsoft_surface_book_claimed_to_be_twice_as&#x2F;cvqgc5u)" rel="nofollow">https:&#x2F;&#x2F;www.reddit.com&#x2F;r&#x2F;apple&#x2F;comments&#x2F;3npv7p&#x2F;microsoft_sur...</a>), I&#x27;m guessing it was made explicit during the unveiling or just after.