The Siemens part number 6AV6381-2CB07-5AK3 refers to the SIMATIC WinCC RC Client Upgrade from V7.2/V7.3 to V7.5 SP2. It’s a downloadable software package designed for upgrading existing WinCC RC clients (excluding RC128). Here's a quick summary:

Type: Runtime/configuration software upgrade

License: Single license (software and license key download only)

Delivery: Digital only; consignee email address required

Languages: Typically includes major European languages

Net Weight: Approx. 0.001 kg

Lifecycle Status: Active

Supported Platforms: Compatible with WinCC V7.5 SP2 environments