Adapt-a-roll 620
Easy to use
but complicated
to load

"It feeds 120 spool but take up spool must be 620"

The Adapt-a-roll 620 was designed to take 6x9 cm roll-film.
The advantage was the easy way to continue shooting just by winding the film to shoot the next picture,
rather than loosing much time to change a film-sheet-holder.
Its clear: advancing the film by turning the knob is far more easy than pulling out the film holder
turn it around and mount the opposite side, lock the holder against the camera back and do not forget to withdraw the dark slide
for the next exposure.
Withdrawing should be done with care holding the camera back firmly with one hand while pulling the dark slide strait out with the other
On the other hand it must be said, that to advance the film in the 'Adapt-a-roll 620' takes also time and winding does not stop automatically after having advanced one frame.

Apart from that, it's not easy to load the "Adapt-a-roll 620".

1)  since there is no more "620" film available, so to use the 620 Adapt a roll one has to spool the "normal" 120 film onto a 620 spool.
2) Threat the 120 paper through the holder and back to the take-up spool.
3)  Close the holder, but leave the dark slide open.
5) Now carefully advance the film by turning the advance knob until the adhesive tape appears. Stop turning the advance knob and close the dark slide.
6) set the frame counter to the black "S" mark.
7) turn the advance knob until the red (1) is opposite the marking line.
8) Ready to shoot your first photo.

  *)According to Dan Fromm who is believed to be a Graflex expert, this is incorrect!
He says that the120 spool, would perfectly fit into the 620 Adapt a roll.
but the film-paper must be  taken up onto a 620 spool.
Unfortunately I can't agree as several 120 spools I tried, did not fit into the spool mechanism.