A holster spacer adaptable for use within a holster assembly including a wearable component and a separable holster supported by the wearable component. The holster spacer includes a wearable component-facing surface, a holster-facing surface opposite the wearable component-facing surface, a mounting interface, an internal cavity provided between the wearable component-facing surface and the holster-facing surface, and a sensor operable to detect a parameter relating to an implement positionable within the holster.