These strings were mounted on a 90cm super-long scale frettless bass guitar, which has a tail piece and a DB-style afterlength. Very few, if any, alternatives are available for this.
They are suitable strings for an instrument like this: they pizz well. However, the balance in tensions between the different strings is not optimal, and this is the only downside.
I have experience with the same strings in 3/4 size on a 3/4 double bass. There they pizz fine too. Initially these solidcores are a bit bright arco, but after a while that wears off, and what remains is a very suitable string, also arco, with an excellent price/quality ratio. Not the best string, but quite suitable.
In 1/4 size there are far fewer alternatives, and this string is a viable choice.