Post sleeves, to screw on need a solid subsoil. Ideally they are fastened onto concrete. Post sleeves are mainly used for the building of fences or similar. Post sleeves are made from relative thin material (2 mm) so that they are only used for light forces. The are not suitable as post anchors or carports or conservatories. Post sleeves are available in galvanized or stainless steel. For the fastening in concrete it's recommended to use Boltanchors . This dowels are able to retain extreme forces. It's not to recommend to use post sleeves for the fastening on plaster.