CREATE TABLE table_31335 ("Manufacturer" TEXT, "Model" TEXT, "Intro Date" TEXT, "Interface" TEXT, "OS" TEXT, "Price  ( USD ) " FLOAT, "Price" TEXT, "Throughput" TEXT)

Who is the manufacturer whose intro date is 2006 and their throughput is 4 mbit/s?
SELECT "Manufacturer" FROM table_31335 WHERE "Intro Date" = '2006' AND "Throughput" = '4 Mbit/s'
SELECT "Manufacturer" FROM "table_31335" WHERE "Intro Date" = '2006' AND "Throughput" = '4 Mbit/s'