CBM 4 New 24"Galvanized Scaffolding Extention Base Plate CBM1290 A Set of 4 New 24" x 1 3/8" Adjustable Galvanized Scaffolding Extension Base Plate. It will fit on 1.69" and 1.625" OD Scaffolding Frames The Base Plate with the 24 stem is adjustable in height The Adjustable Galvanized Scaffolding Extension Base Plate will help you to set your scaffold level IF YOU HAVE ANY QUESTIONS PLEASE CLICK ON (CBM1290) then RETURNS.