Casement window operator

A home owner from San Antonio, TX says:
No markings aside from a "4" on the the back of the crank. Came from a 1920s era house. Mounts directly to the casement window frame, not the wood sill. Thank you!
Window crank
A home owner from San Antonio, TX says:
Additional images.
Casement window operator
Profile picture of Dave Sr.
Dave Sr. from SWISCO responded:
I believe you could have the 39-001 and 39-002 older style casement operators in your windows. Take a look and see if they match up to yours.
A home owner from San Antonio, TX says:
Looks like a match, much appreciated!
Reply to Thread
Use this form to ask a follow-up question or to share your experience regarding this subject.
(your email address will be kept private and is only used to inform you when a response has been made)
Current wait time is 4-7 business days
We promise that one of our experts will personally get back to you as soon as they are able. Thank you very much for your patience and understanding. If your inquiry is time-sensitive, please feel free to reach us at (888) 991-1929 or at