Datum Markers RS10 are precision tools designed for early construction layout, enabling accurate marking of axes and Finished Floor Level (FFL) on slab edges and door or window reveals. Their visible negative imprints provide clear reference points for all trades during interior layout, drywall installation, and subsequent work. These durable plastic markers facilitate easy transfer of axes from slab surfaces to ceiling edges using chalk lines or laser tools, ensuring consistent alignment throughout the building process. Engineered for on-site durability, they withstand the demands of formwork environments for reliable use throughout construction stages.