In this book page 10 the section about Beilinson–Lichtenbaum Conjecture, it mentions that Bloch-Kato implies that $\mathbb{Z}(n) \cong \tau ^{\leq n+1} R\epsilon_*\mathbb{Z}(n)_{ét}$ where $\epsilon$ is the map from étale to Zariski site. I am confused why the truncation is done at level $n+1$ and not $n$. I feel the Zariski motivic cohomology by construction doesn't go above $n$, also assuming the rational compatibility of étale and Zariski motivic cohomology and Bloch-Kato, I am not sure how one can get the one truncated at $n+1$?(I seemingly can get at level $n$ maybe I am missing something.)
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