Imports In N/A, China imported $11.7M in Aluminium Doors, windows, frames and thresholds, becoming the N/A largest importer of Aluminium Doors, windows, frames and thresholds in the world. At the same year, Aluminium Doors, windows, frames and thresholds was the N/A most imported product in China. China imports Aluminium Doors, windows, frames and thresholds primarily from: N/A.