UL-4AAHYB - AA Hybrio Ready-To-Use Rechargeable Battery Retail Pack • 4 pack • 2100mAh • Ready for use just as a disposable battery, it may be used immediately after purchase without the need for it to be charged • HYBRIO batteries last 4x longer on each charge than a standard disposable battery • Rechargeable and Eco-friendly, it may be recharged in any NiMH charger