Hello World!

Was wondering if the 5x7 x-ray film world was as troublesome as the normal 5x7 film world.
What with the issues between the same sized film holder holding an array of film sizes.
I am referring to 12x16.5cm, 5x7in and 13x18cm film all fitting into what is referred to as a5x7in film holder. But not into the same film holder

I guess my question is, if you shoot 5x7 x-ray film, what size inner dimension film holder do you use as well as what brand x-ray film do you use.

Thank you in advance for any information anyone can supply.