Centerline Products. The S version has a brass roller that is covered with a towel strip. A thread tied around the roller keeps the towel strip from unraveling if you accidentally reverse direction:
![CLP 060418 001 CLP 060418 001](https://ogrforum.ogaugerr.com/fileSendAction/fcType/0/fcOid/79705968928449179/filePointer/79705968931235619/fodoid/79705968931235615/imageType/MEDIUM/inlineImage/true/CLP%2520060418%2520001.JPG)
It ain't pretty, but it works.
Comes with AM HiRail trucks and couplers. I changed the trucks to AM scale wheel trucks and added the Snap-Lock coupler on the other end.
I've been using it for well over 20 years in concert with Goo-Gone and have had no issues on either Code 100 scale track and SHS S-Trax. (I really should change the roller cover one of these days...
)
Rusty