Name the transmission for  ps (kw; hp) @4500-6000
CREATE TABLE "table1_21888587_1" (
  "model" text,
  "engine" text,
  "power_rpm" text,
  "torque_rpm" text,
  "0_100km_h_acceleration" text,
  "top_speed" text,
  "transmission" text,
  "co_2_emissions" text
);
SELECT "transmission" FROM "table1_21888587_1" WHERE "power_rpm"='PS (kW; hp) @4500-6000';