Features: DDR4 memory test card is suitable for desktop computer DDR4 DIMM memory. The failures of computer memory mainly due to poor contact of the gold pins, wear and tear of the gold pins, broken PCBs, damage to the data line exclusion, open and short circuits in the video memory, and poor memory performances. LED indicators is used to test all data lines of the memory, and the normal brightness is regarded as normal. When a hardware fault occurs these data lines, bright or no light is abnormal. If test indicator flashes, it means that the gold pins is in poor contact. If there is no indicator light, it means that the hardware have open circuits failure. Check the wear of the gold pins, whether the exclusion is damaged, and whether the PCB is disconnected. Insert the CR2032 battery into the battery holder of test card, or connect the USB C cable , and then insert the memory card to test. Specifications: Component:PCB Size:Approx.150x70mm/5.9x2.75inch Package Includes: 1Pc DDR4 Memory Tester note: 1.Please allow 1-2cm errors due to manual measurement, making sure that you not mind before order. 2.Due to the differences between different monitors, the picture may not reflect the actual of the item.