Navigate to zkteco.com and click on "Support" > "Download Center." You will need a partner login. If you don’t have one, use the "Customer Support Chat" feature and request a direct link for the K40 Pro EQ firmware. Reference your device's serial number.
Warning: flashing device firmware can brick the device or void warranty. Back up configuration and user data first. Proceed only if you accept that risk. zkteco k40 pro firmware download extra quality
Searching for "zkteco k40 pro firmware download extra quality" on Google will yield dozens of sketchy forums (like biometricusers.pro or russian-hack.org). Do not use them. Here is why: Navigate to zkteco