The P-30Ex 30mm Extension Ring from AquaTech increases the length of compatible P-series lens ports by 30mm to allow them to accommodate longer lenses. The ring screws directly onto the housing and the port screws into the ring.
For Use on the Following Lens Ports:
PD-65 dome port with Nikon 14-24mm f/2.8, Tokina 12-24 f/4 II or Tamron 10-24mm f/3.5-4.5 Di LD lens
P-80 flat port with Nikon 17-35mm f/2.8 lens
PD-85 dome port with Sigma 12-24mm f/4.5-5.6 lens