1-year manufacturer's warranty. Writing compatible with all capacitive touch screens: iPads, iPhones, MacBook Trackpads, Magic Trackpads, HTC, Samsung, Nokia, Motorola, BlackBerry. Magnetic storage feature only compatible with 2nd, 3rd, and 4th gen iPad. Locking cap twists on the front (when not in use) and back (when in use). Sound dampening tip simulates the feel of writing with a pen on paper, while also making your strokes quieter. Optimized for a minimum writing angle of 45 degrees. Small plastic disc at the tip of the Jot should not be removed; disc is replaceable. Compatible with most screen protectors, but not with ones that have extra grip, such as Zagg Glossy Invisible Shield, Ghost Armor, Bodyguardz, Skinomi, and Wrapsol.