There's nothing to download. PDF Pack is an online subscription.
Adobe PDF Pack is a bundle of Adobe Document Cloud services.
Adobe PDF Pack works in your web browser on your computer or mobile device, or free Adobe Acrobat Reader software for your desktop. Many features also work in free Adobe Acrobat Reader mobile app.
To use your browser, sign in with your Adobe ID at Adobe Document Cloud
Download Adobe Acrobat Reader DC desktop software. Adobe - Adobe Acrobat Reader DC Distribution
Download the Adobe Acrobat Reader mobile app for iOS from App store, or Android from Play store.
For more details about the service, you may refer this help document FAQ | Adobe PDF Pack.
Hope that information helps.
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