TWO Kirsch FLAT SASH RODS for Top & Bottom Doors & Sidelights 18 - 28 6412-025 by Kirsch

How wide - like are they 1/2 or 1 inch rods?

If I use this for curtains on my glass from doors, how far does this sit off of the window?

I received 2 clear pieces, 2 sash rods, and 4 metal mounting brackets: what is the purpose of the clear pieces? They are too loose to retain slippage.

Can these be used on metal doors or are magnetic ones better for that?