Pella Screen Door top Rod with wheels.

I need a replacement part for my sliding screen door on my pella sliding glass door. Pictures attached. It is a 37 in aluminum rod with approx 1/2"-5/8" inch rollers with a spring return on the top of the door. Appox 39 inch over all. I could not find the serial number of the door. It is a heavy metal sliding glass door. I need the rollers on both ends. I believe one end has a hook for the spring. I am guessing this door was from the 1990's