My school has two tripods for lighting with a crossbar. But we only have one adaptor to make it into a crossbar. We don’t know the make of the tripod so I can’t tell you that but does it matter what adaptor you use? Do they all work or will it be unsafe? here is a pic of what the adaptor looks like sorry this isnt the adaptor we have but its one that looks like it and the one we have hasent got that black stuff on teh staft. the shaft of the adaptor we have has been machened so i dont knwo if that is a factor?