The Polarity changes the colour on the LED. - 3 x Bi-Colour LEDs (Red / White).
Train-Tech LED5 LED Pack Welding Effect (2 Extra Sets)
Train-Tech LED4 LED Pack Fire Effect (2 Extra Sets)
Train-Tech TT1 - LED Multi Gauge Track Tester DCC/DC For N/H0/00 Gauges ++ DSAPo
Train-Tech TT10+ - LED Multi Gauge Track Tester DCC/DC - H0/00/0/G Scales DSAPos
