Ergonomic: easy to use thanks to the 180° movable lever. This makes it a lot easier to put in and take out pages at the left hand side of the system. This is due to the mechanism which opens 50 % wider in comparison to average ringbinders. Robust mechanism guarantees long durability (opening and closing up to 15,000 times). For documents up to size A4. Thickness of cardboard 24/10. chromed metal mechanism. Metal reinforcement. Metal rings. Distance between rings 8 cm. Back 8 cm wide. Dimensions 28.5 x 32 cm. Grey cardboard model: marbled paper, reinforced back with label. Coloured model: covered in recyclable polypropylene. Label holder with removable label.