ITEM NAME:LM317 Adjustable Voltage Regulator Step-down Power Supply Module with L EKN Descriptio n Features: 1. Voltage input range: DC: 3-30V, AC: 3-20V; Can connect the load below 2A, output 1.25V-28V continuously adjustable, wide range of applications. 2. Overheating, overcurrent and short circuit protection. 3. Stable and reliable operation 4. LED Display Screen 5. Applicable to electronic products DIY enthusiasts 6. Easy welding and simple installation 7. Circuit Board Size: 68*50mm Note: 1. This power supply is a step-down module. If the input is greater than the output, the voltmeter below 4.5V will show abnormal, normal output voltage and non-voltmeter quality problems. 3. We have added a new digital voltage display function. The output voltage is clear at a glance. It is very suitable for school students to do experiments. Packaging includes: LM317 Voltage Regulator Step-down Module DIY Suite X 1 We offer you what you need! LM317 Adjustable Voltage Regulator Step-down Power Supply Module with LED Meter.We'd like to settle any problem in a friendly manner. Circuit Board Size: 68 50mm. Overheating, overcurrent and short circuit protection. We want to make sure you are happy with our item. Goods without RMA number will NOT be accepted.