Open a link in resized window within a post

Ok, here’s the situation. I’m trying to this webmaster tools site going. All of the tools on my site are added as posts. Most have a “continue” button, when clicked the results are loaded in the same window from a sub-domain of my site. I’d like the results to open in a new pop-up window with scroll bars instead because the results pages look like a different site. I’ve tried many things and can only get it to open in a new window, but I can’t change the size of it, it loads it full size. Any ideas in here? I’m stuck. Here’s an example of the code I’m using in one of the posts for my site speed checker tool: https://pastebin.com/d6UtGfmK

That example works great, opens in a new window fine, I just need to make it a smaller window more similar to a pop-up. Thanks for any help.