XPimage 0.71x Speedbooster for Pentax 645 Lens to Panasonic Leica L S5II Camera
The 0.71x optic adapter gets rid of crop factor, and increases the aperture. 0.71x optic. STM, S1H, S1RM, the Sigma FP. It's a locking version adapter. which will make the connect of lens / adapter very firmly.