@Ethereal Guitars- its a Titan brand laser. I tried looking it up online- I am not sure Titan makes these anymore- its a self leveling laser that looks like a bar level and comes with a tripod and mounting guide. I found a couple of 7piece Titan level kits online (ebay, aftermarket shops)-for approx $50 usd, but mine is 15 piece and I want to say it was more like $200. I have had it for at least (?) 20 years, possibly more
after looking at your pic above- I am not sure what I am calling my "thin" line is much different than yours. The "thin line" head doesnt project well past about five feet- and what I am calling "thick line" is the head that appears to be for further distances from the level. I will take a photo in the next day or two and post to show you what I am talking about.