Different diameter cameras and different rods have varying capabilities depending on the user’s needs.
To negotiate a 4″ Trap you need a small diameter head and a somewhat flexible rod. Our “Plumbers System” has a 1″ camera and a rod that is flexible enough to go through a 4″ trap.
The larger camera heads and stiffer rods can be pushed much farther than the Plumbers System, but are not flexible enough for a 4″ trap.
Please contact us for more specific answers.