Acorn 1200 series screen door roller.
A home owner from USA says:
August 24, 2016
Screen door roller. Acorn 1200 series. 1301 class. SGD A 12 is all the information I can find. Just need rollers and pins. Thank you. Lynn
Paul from SWISCO responded:
August 26, 2016
I believe your wheel may have come off a roller assembly like our 84-016. This was used by Acorn for their 1200 Series door. Could this be what you want?