A bonnell spring mattress is a type of mattress that is made with a traditional innerspring construction. It consists of a system of interconnected hourglass-shaped springs that are joined together with a wire. These springs provide support and comfort to the sleeper by evenly distributing their weight across the mattress surface. Bonnell spring mattresses are known for their durability and affordability. They offer a medium-firm level of support, making them suitable for a wide range of sleepers. The springs also provide good airflow, which helps to regulate temperature and prevent the mattress from becoming too hot. However, bonnell spring mattresses may not be as motion-isolating as other types of mattresses, such as pocket spring or memory foam mattresses. This means that movement on one side of the mattress can be felt on the other side, which may disturb a sleeping partner. Overall, bonnell spring mattresses are a popular choice for those looking for a budget-friendly and durable mattress option.