Tavik Form Backup Battery. Never get stranded without power again with the Tavik FORM Ultra Thin Backup Battery 1500mAh. With the built-in Lightning connector and ultra thin design, you can keep all your mobile devices powered up and ready to go without the added bulk. -8 more hours of talk time-Ultra thin battery design-Built-in Lightning connector-Stylish anodized aluminum finish. Imported. 3.5" x 2.25".