Yepp, that's correct. Comes with two holes in it. One hole has the small barb in it for the bypass line, the other hole has a plug in it. Pull the plug out and the temp probe threads right in. Use a little Swagelok SWAK (or other pipe sealant. I just used this because I could swipe a little from work) or teflon tape if you please and it seals in the threads without issue.
Doing the Blue Collar bobbers retrofit, I assume?
EDIT: one important thing to note is that the Thermobob 3 unit looks backwards from the previous housings. The cap on the housing faces the radiator, while the other end faces the back of the bike. This is backwards in appearance from previous thermobobs. Bill made sure that I knew this in an email. He's very helpful for tech support. A+ to him as well. He always emails that day, is helpful, and knows what he's talking about. Thought I would mention that.