CREATE TABLE table_49713 ("Model number" TEXT, "Frequency" TEXT, "L2 cache" TEXT, "Mult." TEXT, "Voltage" TEXT, "Socket" TEXT)

What is Frequency, when Model Number is Pentium II 400?
SELECT "Frequency" FROM table_49713 WHERE "Model number" = 'pentium ii 400'
SELECT "Frequency" FROM "table_49713" WHERE "Model number" = 'pentium ii 400'