What weight is this yarn?

There’s some yarn on eBay that I’m eying that says the recommended needle size is 2-4mm. What would you guess the weight is? I was thinking maybe sport?

Edit: I forgot to mention, it’s approx 150yds per 50g.

It could also be a fingering weight. 2mm would be a size 0 in american sizes and 4mm would be a size 6.

It could be sock weight - you’d use 2mm if you were knitting socks and 4 mm for other things, though that’s a bit large and more of a sport or DK needle size. A US 2 is 2.75mm and a US 4 is 3.5 mm which may be more likely for the same weight yarn.

I would guess sock weight with that number of yards for 50g. Can you post a link to the yarn? (I promise not to bid on it!)