Abstract: Methods, systems, and devices for charging a wearable ring device are described. A charging station may include one or more charging elements that are configured to couple with, and facilitate current flow to, corresponding charging elements of a wearable ring device. The charging elements of the charging station, of the wearable ring device, or both may be magnetic so that the wearable ring device is aligned in a charging position when the wearable ring device is inserted into the charging station.

Abstract: Filter devices are provided herein. In some embodiments, a filter device includes first and second resonator stalks in respective first and second openings in a PCB that has first and second metal resonator heads that are on the first and second resonator stalks, respectively. Moreover, in some embodiments, a filter device includes a metal resonator head that has a loop portion on a resonator stalk and a plurality of arms that extend outward from the loop portion.