A carabiner includes a carabiner body, and a gate assembly coupled to the carabiner body. A bit line is electrically connected to the first resistive sense memory element and the second resistive sense memory element. An exercise device conforming to aspects of the present invention provides a foot path that adapts to the change in stride length rather than forcing the user into a fixed size path. The score enables the retention tab to be removed easily without the need for a disadvantageous punched gap between the lead element and the retention tab. The sensor also includes at least one logic or signal processing board populated with components on a first side and a ground plane on a second side positioned toward the RF componentry of the RF board to form an RF shield. The method further includes detecting a liveness gesture based on at least one of a yaw angle of the second image relative to the first image and a pitch angle of the second image relative to the first image, where the yaw angle corresponds to a transition along a horizontal axis, and where the pitch angle corresponds to a transition along a vertical axis.