100% brand new and high quality Features: Made of high quality material, solid, durable and strong conductivity. Large LCD can display input/output voltage, output current/output power/output capacity/output time, easy to read. CNC adjustment is very accurate and fast, and it also can boost and step down voltage. Output voltage can be adjusted from 0.5-30v, while limited current can be adjusted 0-4A as you desired. It features anti-reverse connection protection of input end, which will not burn out, safe to use. Anti-reverse irrigation at the output end, no additional anti-reverse irrigation diode is needed to charge the battery; The module can be set to open/close by default, easy to use. It has multiple software protection mechanisms are available, and the protection threshold is adjustable.When the working parameters of the module exceed the protection threshold, the output will be automatically closed. Output ripple is small and PI filter is available. Thicken radiator fins helps the module to dissipate heat quickly, long service life. Specification: Model: ZK-4KX Material: Fiber glass board, Electronic component Size: 7.9 x 4.3 x 2.6cm/3.11 x 1.69 x 1.02in Color: As picture shown Quantity: 1 Pc Product Parameters: Input Voltage: 5.0-30v Output Voltage: 0.5-30v Output Current: It can work stably at 3A for a long time, and can reach 4A under enhanced heat dissipation. Output Power: Natural heat dissipation 35W; Strengthen heat dissipation 50W Voltage Display resolution: 0.01V Current Display resolution: 0.001A Conversion Efficiency: about 88% Soft Start: Yes (The soft start may fail when it starts with high power and load module.) Protection Mechanism: Input Anti-reverse Connection; Output Anti-reverse Irrigation; Input Undervoltage Protection (4.8-30V adjustable, default 4.8V) Output Overvoltage Protection (0.5-31V adjustable, default 31V) Output Overcurrent Protection 0-4.1A (adjustable, default 4.1A) Overpower Protection (0-50W adjustable, default 50W) Overtemperature Protection (80-110 adjustable, default 110) Timeout Protection (0-100h adjustable, OFF by default) Super Capacity Protection (0-60AH adjustable, OFF by default) Operating Frequency: 180KHZ Note: No retail package. Please allow 0-1cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you Package includes: 1 x DC-DC Buck Boost Converter