These are large, solid and sturdy. Fixed. Not tempered glass. These were removed from the roof of a 1950’s Mountain View, CA school. No cracks or breaks in the glass blocks. We used this larger size at our location as a unique fence/wall. (See photos) Also available in 4′ x 4′.
True measurements: 73 3/4″ x 73 3/4″ x 3 1/8″.
Commercial 1950’s glass and aluminum skylights. We estimate that this size weighs 800 lbs.