Truth opener. 40351 on arm. Patent number4505601. Also has a 35 and the stamped on it. Broke the pin on the bracket that connects to windows
Bob from SWISCO responded:
August 13, 2019
Thanks for writing in. Start by looking at our 39-171 and 39-172 Casement Operators. Go over the dimensions listed on the product page and let me know if you think these are what you need.