Rylo comes with a 16GB SD card that captures about 5000 total photos. Actual photo capacity depends on both the selected bit-rate (image quality) within Rylo's settings and whether or not you have other content present on your SD card.
Rylo is compatible with many SD cards, but to optimize the quality of what you capture with Rylo, we recommend using SD cards with a speed class of UHS Speed Class 3 (U3) or Video Speed Class V30 or higher. If you do use another SD card with Rylo, first make sure it's compatible with Rylo by verifying that it's on our list of compatible SD cards.
For battery life estimates please see our article here.