... of the 68 series aluminum-clad wooden door & window, but also has obvious improvement in sound insulation and ... thorough and permanent tightness. We' ve been strictly carrying out ISO9001-2000 Quality System to control our product quality. ... of window &door, we can supply various windows & doors, like sliding window/door, casement window/door, fixed window/door, awning window, tilt&turn window, swing ...