LIWIN CHINA factory quality control process before shipment: 1) 6 hours continuous working aging test. 2) Connection circuit protection test. 3) Short circuit protection test. 4) Lack of voltage protection test. 5) Over voltage protection test. 6) Flash light concussion test. 7) Quakeproof capability test. 8) Cold warm boot test. 9) Polarity protection test. 10) EMC anti-jamming test. Liwin Electronic Technology Co., LTDwww.liwin-china.com