Works with or without roof racks apparently (I never actually used it). 48" long x 36" wide x 20" tall. Locking keys are missing but the code numbers are visible so you can get new ones from any locksmith like ACME or Prices or online. Keep the dirty stuff out of your car on camping trips. Can also be used for dry secure winter storage or as a bug out container with all your earthquake/bugout supplies ready to throw on the roof of your car. Asking $95 or best offer. Thanks for looking!