NXT NXTRNDNxtrnd Football Leg Sleeves, Calf Sleeves for Men & Boys, Sold as a Pair

Is the product more loose or it is closer to a compression sleeve ?

I'm 5 4 what size should I get?

My son has big calves, 15". The size guide says 10" and up go with the ONE SIZE size option. Are they stretchy enough? He doesn't want super tight.