There isn't any difference in operation of any tuner. As long as they are heavy enough, they all work the same way. And you can adapt other heavy objects to do the task.
Tuna Cans can come with the 1/2-20 thread... or you can get adaptors to go from 1/2-20 to 1/2-28 or 5/8-24
Jerry
Jerry, So you know of a good source for a 1/2X28 - 5/8X24 adapter?
I picked one up on Amazon a while back that while cheap, is pretty loose fitting on the threads.