The Nikon PB-6D Bellows Spacer enables moving a Nikon F6, F5, D2 series or D1 series on the PB-6 Bellows Focusing Attachment rail without interference. It also allows horizontal/vertical changeover anywhere along the rail. Two PB-6Ds are needed with the PB-6; three are needed when using the PB-6E Extension Bellows.
Note:
D3, D700, and D300 may require PB-6D depending on camera orientation