Kato USA Model Train Products UNITRACK Compact Tracks (4-Piece), 183mm/(7") Radius/45-Degree KATO UNITRACK uses a special alloy of nickel silver to prevent tarnishing and reduces the frequency of cleaning that is required The Unit-joiner, a removable wired connector clip, is the basis for KATO UNITRACK's worry-free design Convenient single track pack for expanding from the track sets Reliable and easy-to-use UNITRACK track system makes setting up both temporary and permanent layouts a "snap"