Features: AC 100-240V input voltage range, constant and accurate output voltage. Safety Features: Short circuit, overload and over voltage protection. 300W cooling by interior fans; 20W-50W free air convection cooling (cannot be used in the bathroom). Widely used in scientific and industrial research equipment, LED lighting, electrical equipment, digital products and instruments, etc. Brand : JOOLONPOR Material: aluminum Color: silver Powers: 20W; 25W; 30W; 50W; 300W (optional) Input voltage: AC 100-240V Input Frequency: Output 50-60Hz: 20W: DC 5V 4A 20W 25W: 5V DC 5A 25W 30W: DC 5V 6A 30W 50W: DC 5V 10A 50W 300W: DC 5V 60A 300W 90g / 3.17ounces (20W); 112g / 3.95oz (25W); 175g / 6.17oz (30W) 183g / 6.46oz (50W); 737g / 1.62lb (300W) 20W and 25W: 85 * 58 * 35mm / 3.35 * 2.28 * 1.38 inch 30W and 50W: 110*78*36mm/4.33*3.07*1.42in 300W: 215 * 113 * 50mm / 8.46 * 4.45 * 1.97in Package weight: 104g / 3.67 once (20W); 125g / 4.41 once (25W); 199g / 7.02oz (30W) 201g / 50ml; 783g / 1.73lb (300W) Package Size: 20W and 25W: 90 * 66 * 40mm / 3.54 * 2.60 * 1.57in 30W and 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 confuse the hull with the zero line in order to ensure safety. 3. Please check the terminal attachment again to make sure that the input and output, AC and DC, single-phase, multi-phase, and the positive and negative voltage and current values are correct. 4. Indoor use only! Package list: 1 * Switching Power Supply