Light Fixture Structure

Light fixture structure, for those who know how to install it. I placed an online order and, due to an error, received this item (and was subsequently unable to exchange it). It is brand new. These were the parts I received. Pickup must be arranged in Carnaxide or Charneca da Caparica / Marisol / Aroeira, on a mutually agreed date (only via message on OLX).