U2 is a pilsner beer brewed by Unibroue since 1999. It is redder in colour than Unibroue's other laconically named pilsner, U, to which it is a sort of sequel, if beers can be said to have sequels. Alcohol content 5% by volume.
Source: http://www.unibroue.com/products/u2.cfm (English), http://www.unibroue.com/produits/u2.cfm (French).