I read online that the extension won't work with a Shoei Neotec. That the extension plate was too thick. Is that accurate or not? I have a Neotec II.

I returned this product. The lock combination/mechanism was too hard to reset. If the neotec has a ratcheting lock not a D-ring then yes it is too wide/thick.

Is it the same as Harley Davidson Brand one?

I can't say as I'm not familiar with Harley's lock. I can say this one is great and Ive put one on each bike I ride. The contrasting numbers make it easier to read than some others Ive seen with a sliver wheels on a silver lock

how many tbars come with lock?

If you ordered the lock only, no tbars will come with the lock, if ordered together you will only receive one tbar.

on the T-BAR extension what is the width of the long portion with the hole in it?

I really don´t know. I thougth that the T-bar was include as apperar in the picture, but it is not incle. This T-Bar is very covenient for my helmet. As appear in the picture " Helmetlok Carabiner Style Helmet Lock and EXTENSION" . WHERE IS THE EXTENSION?. I dind´t recive it.