Why choose built-in louver windows between insulating glass blinds inside glass? 1. Operable - ON/OFF depends on you, humanized choices. 2. Energy saving: the insulated louver glass with high shading performance, good idea for the indoor light environment; 3. Less space for installation, save space for today's family requirements. 4. Excellent sound insulation: as insulated glass structure, with excellent noise reduction, if you also need heat reduction or low transmittance, also can choose low-E glass, reflective glass, etc... Hollow Blind Glass, also call built in shutter glass, insulated glass blinds, insulated blind shutter glass, hollow shutter glass, double glass with blinds, built-in louver insulating glass, is a traditional sunshade product with blind inside two glass, which is switchable by manual or by remote control, thus can control the indoor light and privacy freely and easily.