The Lensbaby 8mm & 16mm Macro Converters are compatible with all Lensbaby lens bodies & optics. The Macro Converters attach to your Lensbaby between the lens body & the optic. Pop the Macro Converters into your lensbody & then insert your optic of choice for a great Macro converter. The 8mm & 16mm Macro Converters can be used separately or stacked together to give you a 24mm extension.