It looks like there might be a small typo in your search term. This query could be referring to a few different things, and I want to make sure I give you the right information. Did you mean: Keil MDK-ARM (the microcontrollers development kit)?
File Name: MDK525.exe
File Size: Approx. 680 MB - 750 MB (depending on included packs) mdkarm version 525 download link
Important Note: As of this writing, version 525 is considered legacy. If you cannot find it on the official CDN, it may have been moved to the "Retired Software" section, requiring direct support contact. It looks like there might be a small
Legacy Support: If your project requires support for older architectures (ARM7, ARM9, or Cortex-R), download the Legacy Support Pack after the main installation. Version 5.25 Key Features File Name: MDK525