Unlike the other DVR models they use external flash-memory: SmartMedia cards by size up to 512 Mbytes. Key specifications & features: Dimensions — 45x55x12 mm; Weight — 30 g.; Voice storage capacity — up to 140/280/560/1120 min depending on size of a used memory card 16-128Mbytes; Battery life: recording — 60-70 hrs, stand-by — 3-3.5 months; Battery type: DC 3V x 1, Lithium CR2450