# USB Device Specification — ID 0781:55ab

## Identification
- **Vendor ID**: 0x0781 (SanDisk Corp.)
- **Product ID**: 0x55ab
- **Commercial name**: SanDisk 3.2 Gen1 USB Flash Drive
- **Manufacturer string**: USB
- **Product string**: SanDisk 3.2Gen1
- **Serial number**: 040123d47e7a47e4ac9e89dd25318ac819d7be0fe18a9961190fdffe1052426fd4ae00000000000000000000a8e587bdff867418ab55810792a96c46

## USB Characteristics
- **USB version**: USB 3.2 Gen 1 (SuperSpeed)
- **Negotiated speed**: 5 Gb/s
- **bcdUSB**: 3.20
- **Max packet size (EP0)**: 9 bytes
- **Power mode**: Bus-powered
- **Max power draw**: 896 mA

## Device Class
- **Interface class**: 08 — Mass Storage
- **Subclass**: 06 — SCSI transparent command set
- **Protocol**: 80 — Bulk-Only Transport (BOT)

## Interfaces
- **Number of interfaces**: 1

### Interface 0 — Mass Storage
- **Endpoints**: 2

#### Endpoint IN
- Address: EP 1 IN (0x81)
- Transfer type: Bulk
- Max packet size: 1024 bytes
- Max burst: 1

#### Endpoint OUT
- Address: EP 2 OUT (0x02)
- Transfer type: Bulk
- Max packet size: 1024 bytes
- Max burst: 15

## Functional Role
- USB flash storage device
- Removable mass storage
- No HID or radio functionality

## Operating System Support
- **Linux**: Native support via `usb-storage` / `uas` (fallback BOT)
- **Windows**: Native mass storage driver
- **macOS**: Native support

## Performance Notes
- USB 3.2 Gen1 capable of high throughput
- Real-world speed depends on NAND type and controller
- BOT protocol limits command queueing vs UASP

## Power & Stability Considerations
- High power draw for a USB key (~900 mA)
- Prefer direct motherboard USB port
- Avoid passive hubs

## Recommended USB Port Placement
- Rear motherboard USB 3.x port
- Avoid USB 2.0 ports (bandwidth bottleneck)
- Avoid shared hubs with RF devices

## Typical Use Cases
- OS installation media
- Backup storage
- Large file transfers
- Bootable USB environments

## Classification Summary
**Category**: USB Mass Storage Device
**Subcategory**: USB 3.x Flash Drive
**Criticality**: Low (non real-time device)

