crank handle

We sell many dozens of different handles with a round spline, yes, however there's a lot more that goes into it than just the shape of the spline. I will also need to know the precise diameter of the hole. A photo of the operator would be a huge help as well, if you can submit that to me. 

Once I have those two pieces of information I'm confident that I can make a recommendation.

That unfortunately doesn't narrow it down. There are an absolutely ton of different handles like this with a round hole and the size of that hole is the most important factor. It's not possible to make a recommendation without knowing this measurement.

As mentioned before, a photo of the operator would also be a huge help and would increase the confidence of our recommendation by a lot. At minimum, though, we need the hole size. We can't move forward without it.