The main difference between the PRO version and the usual one is the port for the fiber optic cable and the ability to control the aperture wheel located on the front side of the camera.
SeaFrogs 40M/130FT Underwater camera housing for Sony Sony A9 II + 6" Flat Long Port only (Standard or Flat portnot included).
Full camera control is available, except for the joystick.
Compatible lenses (6" optical glass flat long port):
Sony FE 24-105mm F4 G OSS (Autofocus only, Manual zoom gear not included,purchase here)
Sony FE 16-35mm F2.8 GM (Autofocus only, Manual zoom gear not included, purchase here)
Sony FE 24-70 F2.8 GM (Autofocus only, Manual zoom gear not included, from 24 to 55mm, purchase here)
Sony FE 24-70 F2.8 GM II (Autofocus only, Manual zoom gear not included,purchase here)
In order to connect an external strobe with this housing, it will require to use of a Dual 5-Pin Sync Cord (purchase here) or a Single 5-Pin Sync Cord (purchase here), or a Fiber-optic cable (purchase here)