My husband has tried various other brands of socks ,none of which
remotely resembled the L/XL I chose for him.
He finds Posey socks comfortable and true to advertised sizing.

Whitmyer Cuddles Infant System
Infant Occipital with Infant Sub-Occipitals, Infant Contoured Cradle Pad
Lateral Facial Supports:
Infant Unilateral Support, Infant Bilateral Support
Anterior Support Options:
Dynamic Forehead Strap