Artisan Power Cisco 7921G Phone Replacement Battery. 1400 mAh Cisco 7921G Replacement Standard Capacity Battery. Fully replaces battery number 74-4958-01 and CP-BATT-7921G-STD. Lithium Ion Rechargeable Battery Pack | 3.7 Volt | 1400 mAh | Cells Made in Japan Manufactured by Artisan Power, a leader in premium quality replacement battery packs. Check out the extended capacity battery for an even longer lasting battery. http://www.amazon.com/gp/product/B00FKY286K