Train Tech TTTT1 Multi Scale Track Tester for N/OO9/HO/OO Gauge.
This track tester quickly tests track for power faults. It works on OO/HO and N Gauge track and intervening gauges. The LED Indicates DCC, DC polarity or a fault. Lights Orange on DCC or Red / Green on DC (depending on polarity). It is small enough to check point frogs and blades.