A quick learner from Vermont says:
July 29, 2016
The screw holes are 8cm and the arm is 11 inches. There is no manufacturer only a patent number on the base which is 6,247270. Can you suggest a replacement part
Dave from SWISCO responded:
August 2, 2016
I'm afraid this exact operator is no longer made. I've been able to use our 39-027E in the past by installing the extension arm from off of the old operator. It was a little bit of work, though Check to see if your window has other issues. You might want to replace the complete window.