Casil Honeywell Genuine CA631 6V 3.1Ah SLA Battery for 7845GSM-K14139 Replacement Battery for GSM Communicators Commercial Security Devices from Honeywell, ADT, DSC, Napco, Monitronics 6v 3.2 ah SLA Rechargeable Battery L: 2.41" (61mm) X W: 1.30" (33mm) X H: 3.82" (97mm) Neptune/Casil/Upg Batteries Have Lifetime Technical Support & 1 Year Warranty