REDI2SET glass block windows are the ideal basement replacement window they also make great windows for bathrooms garages kitchens and entryways. Made of 100 real glass REDI2SET glass block windows are fully assembled for easy installation. Thick break-resistant glass enhances home security. Prismatic diamond glass pattern diffuses light and provides maximum privacy. Provides improved energy efficiency over old single-pane basement windows. Efficient sound barrier reduces noise from outside and helps keep homes quiet. Assembled in the USA by 1 of Americas oldest glass block companies. Non-vented option features clean all-glass look. Rough openings should be 12-in to 2-in larger than the actual window size.