A completely unused 1GAL container off foundation armor: Armor SX5000 Penetrating Silane Siloxane Concrete Sealer and Masonry Water Repellent.
We just unscrewed the cap last week, but ultimately decided to paint the surface instead of sealing it. It’s been kept inside our house and we have not used a single drop of it.
From my research, this appeared to be the best concrete penetrating sealer that contractors use and does not change the appearance of the concrete. Refer to the manufacturer’s product info here: