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.
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