黒いチェアーは過去に入荷したもので背もたれ角度が105°になっていますが茶色のチェアーは一番最近入荷したものになりますがご覧の通り背もたれ角度が全く異なります。測ってみたところ95°です。
The black chair is the one which we get in the past and its angle is 105.
The brown one is the one which we get recently and its angle is different from the previous one totally.
We checked and the angle is 95.
