The Unique Wire Tuner was produced some years ago by Unique Wire Products. I don’t know anything about the company nor when these were made but they are very desirable single wire feed antenna tuners. They get great reviews on eHam.
In researching this device it appears that the company produced at least two versions, one being the regular version and the other a wide range version. What is interesting is that I have found several variations of the two main versions. The version numbering below is just for reference, not the actual version number from the manufacturer. Some of these may arguably be user modifications. Readily apparent differences are that versions 1 and 4 have smaller variable capacitors, and versions 3 and 5 have doorknob capacitors though a different number and in different configurations.
There was an article in QST that referred to these tuners in October 2004. A copy of a manual for the version that I own (v3) is here. There may well be other versions of the manual.
I don’t have an internal picture for this version.
This the one that I own.
The manual states that the roller inductor is 28uH, the variable capacitor is 25 pF to 600pF, and the two 1000 pF doorknob capacitors provide a range of 25 pF to 1600 pF.