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.
40M/130FT Underwater camera housing for Sony A7R IV
Full camera control is available, except for the joystick.
SeaFrogs 6" optical acrylic Dry Dome Port V.7
6" Dry Dome Port V.7 with a lens shade. Created specifically for underwater photography.
Compatible lenses (Dome port)
Samyang AF14mm F2.8 FE and Sony FE 28mm F2
Sony FE 28mm F2 + Fisheye Converter
Sony FE PZ 16-35mm f/4 G (Autofocus only, Manual zoom gear included)
Flat Long port
Created specifically for underwater photography including the ability to use manual focus.
Sony FE 24-70mm F4 ZA OSS (Autofocus only, Manual zoom gear - purchase here) Works from 35mm to 70mm
Sony FE 90mm f/2.8 Macro G OSS (manual focus available,gear included)
Sony FE 24-105mm F4 G OSS (Autofocus only, Manual zoom gear - purchase here) - Works from 28mm to 65mm
Materials :
Polycarbonate
ABS plastic
Optical glass
Stainless steel
EPDM rubber
O'ring sealed buttons with spring
Optical acrylic
Key features:
Vacuum Pump System port
Inbuilt leak detection sensor
Interchangeable port system
Synchro cable port
Dual Fiber-Optic port (Sea&Sea type)
Long flat port (Optical glass)
6" Dry dome port (Optical acrylic)
Stainless steel mounting plate 1/4" Thread
40m / 130ft Dept rate
The reinforced metallic bottom plate
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) with a Flash trigger (purchase here)
Compatible lenses & ports list 
