Synergy Digital Cordless Phone Battery, Works with Siemens Gigaset A120 Cordless Phone, (Ni-MH, 2.4V, 650 mAh) Ultra High Capacity, Compatible with GP 55AAAHR28MX Battery - Walmart.com
Siemens GIGASET 4200 Cordless Phone Battery Replacement for 4 AA NiMH 2800mAh Rechargeable Batteries - Newegg.com