Green house door skate J11

It's a replacement piece for green house tpye green protect.

Part number J11 see  mounting plan 

Patin de porte pour serre green protect.
Numero de la piece J11 sur le plan de montage

https://www.ma-serre-de-jardin.com/serre-de-jardin-en-verre/13450-serre-de-jardin-1452m-en-aluminium-anthracite-et-verre-trempe-4mm-green-protect-3336363134500.html