What is "talatat"

Talatat are stone blocks of standardized size (ca. 27 by 27 by 54 cm, corresponding to ½ by ½ by 1 ancient Egyptian cubits) used during the 18th dynasty reign of the Pharaoh Akhenaten in the building of the Aton temples at Karnak and Akhetaten (modern Amarna). The standardized size and their small weight made construction more efficient Their use may have begun in the second year of Akhenaten's reign. After the Amarna Period talatat construction was abandoned, apparently not having withstood the test of time.