Suit for interior lighting in buses, streetcar or tramcar, trolleybus, electric vehicles, ... filament preheat enable 100,000 times of switching service for one tube.3.20,000 hrs of serve with ... protective circuits for over-voltage, under-voltage, short-circuit and bad ... or dismount.7.All fluorescent lamps suit for SMEST DC/AC ballasts.Note:For above, lamp length, tube number ...