Specifications:  Input voltage: 220V±10%@50Hz, or 110V±10%@60Hz, manual switching.  Output Voltage: 0-30V.  Current: 0-5A.  Working environment: Temperature: -10 ° C ~ 40 ° C Relative humidity: <80%.  Storage conditions: Temperature: -20 ° C ~ 80 ° C Relative humidity: <70%.  Power effect: CV ≤ 0.1% + 10mV , CC≤0.1%+10mA.  Load effect: CV≤0.1%+5mV , CC≤0.1%+10mV.  Ripple and noise: CV≤10mV r.m.s. , CC≤20mA r.m.s.  Display mode: 4-digit LED digital display.  Display accuracy: ±0.1% ± 1 word.  Size: 285*128*145mm.  Pressure test:  Input-output: 1.5KVAC/1 minute.  Input - Housing: 1.5KVAC / 1 minute.  Output - Housing: 500VAC / 1 minute.  Grounding resistance: <20mΩ.  Appearance size: length 285mm* width 128mm* height 145mm (excluding protruding parts).     Features:  -- Provide 5V2A USB interface.  -- 4-digit number shows current voltage and power.  -- Single output, high precision, high reliability, low ripple and noise.  -- There are many protection functions such as temperature, overload and current limiting.  -- With voltage / current coarse adjustment knob, can adjust the voltage / current value accurately.     Application range:  -- For teaching experiments, research.  -- For the repair of communication equipment.  -- Other areas that require DC regulated power supplies.  -- Testing and aging for electronic production line products.     Package Included:  1 x DC Power Supply.  1 x Power Cord