Described herein is an adaptor configured to be selectively mated with a device, such as an activity monitor, to enable the device to be clipped to a persons finger or clothes, instead of being strapped around a wrist. The adaptor includes a base, lever and hinge. At least one connector extending from the base and is configured to mate with a portion of the device to thereby selectively mate the adaptor with the device. The base includes an opening sized and positioned to enable a distal portion of a persons finger to extend through the opening and contact the device when the adaptor and device are mated and the device is clipped to a persons finger. This enables the persons skin to be in contact with at least one sensor of the device, to thereby enable the device to perform functions that rely on the sensor(s) contacting a persons skin.
