Features: AC 100-240V input voltage range, steady and precise output voltage. Safety features: short circuit, overload and over-voltage conservation. 300W cooling by inside fans; 20W-50W cooling by free air convection (can't be used in bathroom). Widely used in industrial, scientific research equipment, LEDs lighting, electrical equipment, digital products and instruments, etc. Specifications: Brand: JOOLONPOR Material: aluminum Color: silvery Powers: 20W; 25W; 30W; 50W; 300W(optional) Input voltage: AC 100-240V Input frequency: 50-60Hz Output: 20W: DC 5V 4A 20W 25W: DC 5V 5A 25W 30W: DC 5V 6A 30W 50W: DC 5V 10A 50W 300W: DC 5V 60A 300W Item weight: 90g / 3.17ounce (20W); 112g / 3.95ounce (25W); 175g / 6.17ounce (30W) 183g / 6.46ounce (50W); 737g / 1.62lb (300W) Item size: 20W & 25W: 85 * 58 * 35mm / 3.35 * 2.28 * 1.38in 30W & 50W: 110 * 78 * 36mm / 4.33 * 3.07 * 1.42in 300W: 215 * 113 * 50mm / 8.46 * 4.45 * 1.97in Package weight: 104g / 3.67ounce (20W); 125g / 4.41ounce (25W); 199g / 7.02ounce (30W) 201g / 7.09ounce (50W); 783g / 1.73lb (300W) Package size: 20W & 25W: 90 * 66 * 40mm / 3.54 * 2.60 * 1.57in 30W & 50W: 115 * 82 * 42mm / 4.53 * 3.23 * 1.65in 300W: 220 * 117 * 57mm / 8.66 * 4.61 * 2.24in Notes: 1. Please allow 1-10mm error due to manual measurement, thanks for your understanding! 2. Do not mistake the shell on the zero line in order to ensure safety. 3. Please check again the attachment of terminals to ensure the input and output, ac and dc, single phase, multiphase and the positive and negative voltage value and current value is correct. 4. Indoor use only! Package List: 1 * Switching Power-Supplys 1 * Switching Power-Supplys