Duracell AGM or Absorbed Glass Mat batteries have no free-flowing acid. Special micro-fiber glass mats absorb the acid so the battery will not spill or leak. They are held tight against the battery's power-storing components and have a lower electrical resistance for quicker starting power.
This glass mat material also helps protect and reinforce the battery's internal components making it extremely resistant to vibration or shaking damage. Reinforcing the battery's internal components also improves the battery's ability to withstand demanding accessory loads. It is one of the most durable and dependable designs for your vehicle.