Bonjour4 Pairs of Boys High Performance Thermal Ski Socks Multi Pack (9-12/4-7 yrs) & (12-3/7-10 yrs)

My son is a junior size 2.5 in clark’s shoes. which sock size would you recommend for him? the sizes listed here are 9-12 or 12-3.5?

9-12 is age or size? My 2 years old son wears size 9 shoes. Also is it good for snow boots ?

Hi when the description says ‘grip zones’ does it mean the little sticky pads on the soles like slipper socks?