See sketch for dimensions.

Price is for one

Inswing only.

In order for this to work:

You need to put a piece of wood behind the faceplate (with the 3 screw holes) above the swivel point of the arm.

In used working vintage condition. 
Only this one has been cleaned.

The other ones are dirty with a century of grime, paint and dirt on them.
Took me about 10 minutes of cleaning to get this result.
The paint comes off with dish soap and a brass bristle brush.
Recommended to oil with WD40 or machine oil, for ease of use and to add an nice sheen.
Design is Arts and Crafts.
Color is dark oil rubbed antiqued bronze.
The sliding slot is 7 inch long, and the total length when shut 13-1/4".
The handing is reversible for both left and right handed hinged inswinging casement windows.
The pivoting arm should go underneath the window sash, and the small bracket is connected to the window sill. 
The knob and curved cover plate should be facing you and is connected to the window sash.

3735-50