CREATE TABLE table_6439 ("Location" CLOB, "Culture" CLOB, "# found" CLOB, "Ball diameter" CLOB, "Period" CLOB)

What's the Ball Diameter with the Location oof El Manati, and the Period of 1200 BCE?
SELECT "Ball diameter" FROM table_6439 WHERE "Location" = 'el manati' AND "Period" = '1200 bce'
SELECT "Ball diameter" FROM "table_6439" WHERE "Location" = 'el manati' AND "Period" = '1200 bce'