> ## Documentation Index
> Fetch the complete documentation index at: https://docs.wuji.tech/llms.txt
> Use this file to discover all available pages before exploring further.

# Version Identification and Differences

<Info>
  This page applies to both revisions and appears under each. For the Wuji Hand 2.1 (Beta) documentation, see [Wuji Hand 2.1](/en/docs/wuji-hand/beta1/overview/).
</Info>

## Identify the Device Version

Check the serial number first. If positions 5–7 are `A00`, the device is Wuji Hand 2.1 (Beta). If positions 5–7 are `A01`, the device is Wuji Hand 2.2 (Beta).

## Hardware and Software Compatibility Matrix

| Component | 2.2 (Beta) | 2.1 (Beta) |
| - | - | - |
| <span className="nowrap">Power and interfaces</span> | <span className="nowrap">11–13 V DC</span> input (12 V nominal). <span className="nowrap">XT30 + RJ45</span> two-cable layout. See [User Notice](/en/docs/wuji-hand/latest/user-notice#power-safety) | <span className="nowrap">12 V DC</span> only, other voltages aren't compatible. Interfaces are the same as Wuji Hand 2.2 (Beta). See [User Notice](/en/docs/wuji-hand/beta1/user-notice/#power-safety) |
| <span className="nowrap">Firmware</span> | v2.0.0 and later, currently v2.5.1 | Stays on v1.2.4 and receives no further updates |
| <span className="nowrap">Wuji SDK</span> | Upgradable to the latest version | Upgradable to the latest version, with some capabilities unavailable (see below) |
| <span className="nowrap">Wuji CLI</span> | Supported, pushes the firmware package that matches the hardware revision | Same as 2.2 (Beta) |
| <span className="nowrap">Wuji Studio</span> | Archived and no longer maintained. Use the Wuji CLI for firmware upgrades | Same as 2.2 (Beta) |
| <span className="nowrap">Simulation models</span> | `hand2/hand2_beta2/body/`, ROS 2 package `wuji_hand2_beta2_description`, models named `wujihand2-beta2-{side}`, USD entry `wujihand2_beta2.usd`, plus an added fingertip soft-pad link. The two package names differ, so both revisions coexist in one workspace. Loading works through the same links as Wuji Hand 2.1 (Beta), and the asset list is in the [Model Assets](/en/docs/wuji-hand/latest/hardware-integration#model-assets) | `hand2/hand2_beta1/body/`, ROS 2 package `wuji_hand2_beta1_description`, models named `wujihand2-{side}`. To load them, see [Get and Load](/en/docs/wuji-hand/latest/hardware-integration#get-and-load) |
| <span className="nowrap">Back-of-hand status light</span> | Supported, with L0–L3 levels, requires firmware v2.2.0 or later (see [Product Introduction](/en/docs/wuji-hand/latest/product-introduction#back-of-hand-status-light)) | Supported, with priority numbering (requires the matching hardware batch) |

<Info>
  For Wuji Hand 2.2 (Beta), upgrade the firmware and the Wuji SDK together, following their own release notes for version requirements. The Wuji SDK interfaces work on both 2.2 and 2.1 devices, and the capabilities below depend on hardware, so they stay unavailable or behave differently on a 2.1 device even after a firmware and SDK upgrade.
</Info>

## Back-of-Hand Status Light

| Item | 2.2 (Beta) | 2.1 (Beta) |
| - | - | - |
| Light scheme | L0–L3 levels | Priority numbering |
| Hardware prerequisite | Standard | Requires the matching hardware batch |
| Without status-light hardware | — | No light output, and the call raises no error |

The level-based scheme on Wuji Hand 2.2 (Beta) requires firmware v2.2.0 or later. For what each level means, see [Back-of-Hand Status Light](/en/docs/wuji-hand/latest/product-introduction#back-of-hand-status-light) in Product Introduction.

## Internal Field Differences

The device-internal fields of `Hand2CommSummary` depend on the firmware version on Wuji Hand 2.1 (Beta). The exact version threshold isn't published yet and will follow in a later update. For the field definitions, see [Data Types](/en/docs/wuji-hand/latest/sdk-reference/diagnostics#hand2commsummary) in SDK Reference.

## Capability Limits After a Wuji Hand 2.1 (Beta) SDK Upgrade

* Back-of-hand status light: devices without the status-light hardware produce no light output


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