Roller unit for screen door

The corner can be replace with the 95-020 Acorn Patio Screen Door Corner. It is compatible with a few different rollers. Since your have a metal wheel, I've narrowed down the possible options to the 84-091M and 84-104. 

Carefully look over the dimensions for each part to confirm that they're the right replacements. Be sure to double check the diameter of the wheel on the rollers.

Alternate view of 95-020

Dimensions for 95-020

Sure! Take a look at the 84-016 to see if it is a better fit. It has a 1-1/4" nylon wheel.