Truth 23 series Right Hand 11 Inch Single Arm Rear Mount Casement Operator with Round Shoe
The 11 inch has been discontinued by Truth and are Custom made when needed.

Crank handle is sold separately.

Arm Length: 11 Inch
Arm Width: 11/16 Inch
Screw Holes: 3-7/8 Inch & 4-3/4 Inch
Roller Diameter: 9/16 Inch
Mount: Rear
Roller: Stainless Steel
Handed:  Yes, As shown 
Available Colors:
Black
White
Chestnut Bronze

Contents: one operator, No Screws, No Crank Handle 
Priced and sold each.
Note:
This Truth operator is made with 7-1/2, 9-1/2, 13-1/2 inch arms (11 inch Discontinued) Assorted Colors: White, Bronze, Chestnut Bronze and Black.
The 11 inch arm may be replaced with the 9.5 length