OLD STYLE Roto Pro-Drive Series Operator for Vinyl Awning Windows. Has a hole that crank handle fits into.
Handle sold separately.
The Pro-Drive has been discontinued and is replaced with the X-Drive. They are interchangeable except for the handles.
Limited to existing inventory - when gone you will need the new style.

Measurements:
Arm Length: 13-3/8 inch
Outer screw hole centers: 3-3/16 inch
Body Width: 4-9/16 inch
3/8 inch diameter hex spline

Related Parts:
57051 - Mounting Bracket, Face mount
57050 - Mounting Bracket, Surface mount

Note1:
The X-Drive and Pro Drive are the same operator that uses a different crank handle.
The Pro drive operators have a hex shaped hole in the operator and the handle with a 5/16" hex stud pushes into operator.
The X-Drive has a 5/16" Hex spline that protrudes from the base and the handle fits onto it.

Note 2: Roto Awning Operators for vinyl windows have a flat base, the wood window operators are notched