If you specifically need version 4.2.1 for older hardware compatibility, it is best to check the archives on the GSMHosting forum rather than third-party "fast download" sites.
Advanced "Auth" sideloading, OTA flashing by IMEI/SN, and bootloader unlocking (V2) with 2FA support. download eft pro 421 hot
The Easy Firmware Team frequently posts direct download links for "hot" updates on their Official Facebook Page . If you specifically need version 4
ADB translation without themes for various languages and support for Android versions 10 through 14. OTA flashing by IMEI/SN