... .Small volume,light weight,high efficiency.100% full-load burning test ,1 year warranty.Protections: short circuit,overload .Cooling by free air ... solder ,lack of components, no tin dross, no short-circuit, no open circuit, no bad led indicator ,no high voltage, no low ... bonding, etc6.Visual full inspection: to make sure no scratched case, no cracked wires ,no missing screw, no label misaligned, etc2 ...