That's it, makes your life easier when fitting the scuttle as no need to take a big chunk out of the base to allow it to fit. Also helps with the sides whether using grp or ali...I used to use two bits of 1" diameter tube welded onto the inside rail then made a hoop in 3/4 diameter tube, plop that into the 1" diameter tubes and angle it to suit then weld it up....neat and very simples