The Lensbaby Macro Converter Extension Rings lets you take that Lensbaby look as close to your subject as you want - even touching it in some cases - and get a picture that's in focus. You can choose the 8-mm ring, the 16-mm ring (both included), or combine them for a 24-mm ring, so you have plenty of control over exactly how close-up you want your photo to be. The converters are compatible with all Lensbaby lens bodies and optics, and provide focus distances of 0 to 8.13, depending on the optic, the camera, and the converter(s) you use. The Macro Converters simply screw into the Lensbaby lens body and the optic screws into the converter. The converters are compatible with Composer, Composer Pro, Muse, Scout, Control Freak and all optics (the Fisheye Optic is only compatible with the 8-mm converter, as it allows you to actually focus on a subject that the lens is touching).