plug system with sideways locking device: distance sleeve and plug head for wall mounting signs with 9 mm drill holes (16 mm for the 50 mm diameter version), made of rust-free stainless steel (AISI304), cut with facets, comes with screws, dowels, glass protective rings and headless screws for security (for quantity see the number of wall fasteners (sleeves)), includes Allen key, given dimensions: d = distance between wall and back side of the sign, th = feasible thickness of the sign