That looks like some lovely handmade thread. The item description says: thread thickness 40x3 - size 40, 0,04 mm. I found
an article that suggests this is derived from Japanese factories. The 40 is equivelent to US 40WT and the 3 is the number of piles used to make the thread.
This article suggests “90/14 for 40 weight threads” for sewing machines.
This article suggests “ If your thread is heavier, 40, 30, 28 or 12 wt, use a larger needle: 90, 100, 110.” for hand sewing.
I feel like a total charlatan because I knew absolutely nothing about sewing until a couple of weeks ago and I think researching this, I’ve just doubled my knowledge . . . And realised how confusing this all is.
I’m sure an expert will come along and give a way better
answer.