Actually, the 'custodian helmet' is a pickelhaube.

Claverhouse said:

Actually, the 'custodian helmet' is a pickelhaube.

She's wearing a Kask m/1887. According to Swedish Wikipedia, a "kask" is an older military helmet of stiff leather, cork or metal, generally with a visor both in the front and the back. They are often tall and have have a spike or comb at the top. Helmets for police and firemen are also often called "kask". The Swedish Wikipedia page links to Custodian Helmet on the English Wikipedia, so that was all I had to go on.

But thanks for the pickelhaube tag. I didn't know that word. I need to change the tag in a few other posts.