bathroom acrylic block window casement crank

Hi
This crank no longer catches along the teeth/wheels and I am trying to replace it. The window was installed in 2000 by a contractor during a renovation so it may be off brand/no label. There is no name on the crank or the window that we can see, only the number (part number?). The arm is 4 inches, the housing (closed part) is 5 inches and the long arm is a little over 11 inches, the shorter arm is about 4 inches. any help for a replacement would be greatly appreciated! My handyman is very handy so a close approximation might work.
thank you
j

Hi Emily and Swisco team. The part works great! thank you. However, we couldn't get the cover off the old part and need a new cover/handle. Can you help me with the right part to order in white? thank you