This knob gives you a secure handhold without blocking the screen of your smartphone. The two-piece design is composed of a low-profile magnetic disc that installs on the phone (or a rigid case) and a rubber-tipped aluminum knob. The knob (3/4" in diameter, 1" tall) attaches instantly and securely to the magnet to provide a comfortable grip, and also acts as a prop to hold the screen at a comfortable viewing angle when set on a flat surface.
You can detach the knob to store the device in a soft-sided case or sleeve; at only 3/16" thick and 3/4" in diameter, the magnetic disc doesn't get in the way.
Additional bases and magnets are available separately.