This is a small plastic device with pins on it. It is used to physically reset the ink level chips on the cartridges.
Open the downloaded .zip or .rar folder (often requires the password "Epson L3150") and run AdjProg.exe as an administrator.
Press and hold the following buttons on your printer:
When the "Service Required" message appears on your Epson L3150, it usually indicates that the waste ink pads have reached their limit. Using an (Resetter) allows you to reset the internal counter so you can resume printing. How to Use the Epson L3150 Resetter Tool
Epson printers include a "Waste Ink Pad" designed to soak up excess ink during cleaning cycles and borderless printing. To prevent ink from leaking onto your desk, the printer's software tracks how much ink has been absorbed. Once the internal counter hits 100%, the printer locks itself for safety.
Resetting the software counter does not physically clean the waste ink pads. After 1–2 software resets, you should physically replace or clean the ink pads
: The printhead and internal parts can become very hot during use. If it overheats, the printer may pause or stop printing entirely until it cools down. How to Reset the Waste Ink Pad Counter