Bellows Focusing Unit PB-6. The PB-6 renders reproduction ratios to nearly 11X, depending on lens used and mounting configuration. Its modular design offers a versatile system of close-up and macrophotography. Operates with manual or aperture-priority auto, TTL metering and flash control. Extension range is 48-208mm. Supplied with Front Standard, Rear Standard, Rail Assembly and Bellows.