What is the headphone model with a plastic construction and a prestige headphone class?
CREATE TABLE "past_production" (
  "headphone_model" text,
  "headphone_class" text,
  "sensitivity_d_b" text,
  "impedance_ohms" real,
  "driver_matched_d_b" text,
  "construction" text,
  "earpads" text,
  "termination" text,
  "succeeded_by" text
);
SELECT "headphone_model" FROM "past_production" WHERE "construction"='plastic' AND "headphone_class"='prestige';