Bonnell type springs. The current world standard for springs and spring unit of this type is the result of our research and development.
In Bonnell type spring un its, the springs are linked by a spiral. The 5/4 or 4/3 spiral passage system is an important indicator of quality. This system was developed by us and quickly became a world standard. This guarantees firmness and unaltered spring unit shape tolerance - what mattress manufacturers demand. In addition, this system requires fewer spare parts.