The second one is more beefy and can handle tips with a diameter up to 18mm.
This model offers also a wider range for fine adjustment (if your lathe isn’t “dead nuts”).
For the rest both models are identically constructed.
So, if you have to install a cue tip with 15,1 mm dia the first one will not work.
sounds good, howevere your video doesn't do much in the way of selling or showing how this centering tool actually centers the tip
No malice intent , just that there are no more details, videos can be edited etc. I trust that you didn't edit, however this video did not show how this tool works.
Obviously anyone that could use such a tool, already has a lathe at their disposal.
If you have any basic machining skills, then you should be able to make this tool in about 10 minutes.
JMO
Rudie