pool pump to filter hose

I have a pentair ST-50 filter P/N 180220

I have a Dynamo Pump Model Dynii-ni-1

My hose between the two is old and starting to leak.

What is the replace part for that?  and hose length, thread size?

The replacement hose is part number 4600-0001. That will connect the ST-50 and Dynamo pump. It’s approximately 20". I don’t have the thread size measurement.