For Sale is a pair of Jagwire Pro Indexed 4mm Inline Gear Cable Tension Adjusters
Great for adjusting front derailleurs.
One may have had very light usage the other is 100% new. I think one was fitted to a bike then not required as the adjustment was done at the front derailleur instead.
Any questions please ask, and please check my other listings for more bike parts (including crankset)!