This mattress, with 420 full springs, offer the following to the consumer:

• Active pocket springs provide very precise body support and relieve pressure on your shoulders and hips.
• Top layer of high resilience foam and extra wadding adds extra comfort.
• Stretch fabrics on the top side of the mattress ensures more precise support for your body.
• The spring construction allows air to flow through the mattress so it stays fresh.
• Reversible. Use both sides for even wear and long-lasting comfort.

Via Ikea