TTTT10 Multi Gauge Track Voltage Tester For OO/O/G ScalesThis track tester quickly tests track for power faults. Low cost and easy to use Works on OO HO, O & G 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 Improved plus design now features tough resin sealed circuitry. Pack includes 1 TT10+ Track tester and detailed instructions (Track shown is not included).