〜ものの

買ったものの、一度も使っていません。

Katta mono no, ichido mo tsukatte imasen.

I bought it, though I have never once used it.

ものの is the written concessive: the first holds, but the expected result does not follow

引き受けたものの、自信がありません。

Hikiuketa mono no, jishin ga arimasen.

I took it on, but I have no confidence.

The first half often concedes with a 〜は〜た shape

けれど より硬く、論文に向きます。

Keredo yori kataku, ronbun ni mukimasu.

Stiffer than けれど, and suited to papers.

In speech けど is enough