This is a Dutch Army Military Cap / Infanterie Kepie model 1916 M16 laag model. The coackarde in yellow silk indicates it was for “onderofficieren”. The CS insignia stands for “Cadettenschool”.
In pretty good condition for it’s age, only the inside top cloth has some damage because of wearing. There are some remains of a makers label and size 54,5 label inside.
Hard to find, these early low size “Kepies” are much rarer than the later higher ones!