SMAKN&reg; DC/DC Converter 24V Step Down to 12V/6A Power Supply Module This module has synchronous rectification. And the efficency is up to 96% with low calorific value. The function of this module hasover-curren protection and short-cirsuit protection. It can work normally after remove away the problems. But it has no reverse polarity protection. so Don't conect it reversely This module has:waterproof! Dustproof! Shockproof! Three function integrate with one, USES the high quality transparent epoxy glue potting. And it has Aluminum alloy Shell. so the heat dissipation is good. Can be widely used inbus, large trucks, cars, solar power, bus display, taxi advertising screen, etc.it never influence car ridio,the stereo, LCD TV, LED, car navigation, walkie-talkie and monitoring system, easy to deal with the bad environment.