Features 1Easy Operation: Individual silicone buttons of buck boost converter set voltage or current. 1 click to enter, 1 click to exit, fast and simple, refuse tedious. 21.8 Inch LCD Display Panel: Step up down power supply has a 1.8in LCD display that you can see clearly the data for convenient operation, improving efficiency. 3Enhanced Performance: Buck boost module features upgraded power, thickened heat sink, external fan port for optional expansion. More reliable and stable connection for upper and lower boards. 11 storage spaces available. 4Multiple Protections: Buck boost converter features reverse connection, backflow prevention, undervoltage safety, overvoltage safety, overcurrent safety, overheating safety, overpower safety, timeout safety, overcapacity safety, and overenergy safety. 5Independent Upper and Lower Board Architecture with Independent MCU: Convenient replacement of LCD or color screen display panels. Power board can be used independently. Specification Item Type: Buck Boost ConverterMaterial: ABS, Silicone, Aluminum AlloyInput Voltage: 6-36VOutput Voltage: 0.5-36VOutput Current: 0-4.5AOutput Voltage Accuracy: 0.3%+3 digits (calibratable)Output Power: 40WCurrent Resolution: 0.001AData Group Storage: 11 groupsScreen Size: 1.8 inch upgraded screen, Approx. 36 x 29mm / 1.42 x 1.14in visible areaConversion Efficiency: Approximately 88%Buzzer: YesSoft Start: YesSafety Mechanism:Input Reverse Connection Safety: YesOutput Anti backflow Safety: YesInput Under Voltage Safety (LUP): Adjustable from 5.5-35V, default value 5.5VOutput Over Voltage Safety (OUP): Adjustable from 0.5-37V, default value 37VOutput Over Current Safety (OCP): Adjustable from 0.001-4.6A, default value 4.6AOutput Over Power Safety (OPP): Adjustable from 0.01-41W, default value 41WOver Temperature Safety (OTP): Adjustable from 30-99, default value 90Time Out Safety (OHP): 1 minute to 99 hours 59 minutes, default value offOver Capacity Safety (AH): Adjustable from 0.001-9999Ah, default value offOver Energy Safety (OPH): Adjustable from 0.001-4000KWh, default value off Package List 1 x Step Up Down Power Supply