Methods for determining a concentration of an analyte in a sample, and the devices and systems used in conjunction with the same, are provided herein. The apparatus and methods generate three-dimensional images for an observer by providing components of the image in a series of frames to an image space. The annular slit is meander-shaped around the periphery of the coupling so that radially outward protrusions of the inner ring undercut radially inward protrusions of the outer ring. The image displayed on the display panel is separated by parallax in the separation area. For example, it is determined if a feature has been used by a client. The brake assembly includes a fastener extending through each of the second openings of the backing plate and into the drum-in-hat adapter to thereby secure the backing plate to the drum-in-hat adapter.