CREATE TABLE table_71453 ("Call sign" TEXT, "Frequency MHz" FLOAT, "City of license" TEXT, "ERP W" FLOAT, "Class" TEXT, "FCC info" TEXT)

\What is the class of the station with the call sign w254ah?
SELECT "Class" FROM table_71453 WHERE "Call sign" = 'w254ah'
SELECT "Class" FROM "table_71453" WHERE "Call sign" = 'w254ah'