Most of the info is contained in the pictures. There is no instruction sheet b/c the instructions are on the box. However, I went to the trouble of digging out a standard size toilet seat in basement storage that I've saved as some sort of emergency preparedness item... or b/c I didn't know camping was so posh as to have electricity and running bathrooms, lol. Mounted it on top of my elongated toilet & took pics of how it would work... after I took everything off and cleaned my toilet 1st of course. ;-) NOTE: this will not work with a soft cushioned seat b/c it will be too thick for the trainer seat to lie flat. I had a soft cushioned seat but it still works to show what it would be like.
The space from center slot to center slot of the mounting base is 5 1/2 inch. I also looked it up online and it said it fit most standard toilets. So take a look at the additional pics and let me know if there is anything else I can tell you. I'll c&p above what I found online about it, mainly just advertising points. Ty for your interest.