Apple Universal Dock

The Apple Universal Dock is a series of docks from Apple for early iPods and iPhones with 30-pin dock connectors.

Universal Dock system
The Universal Dock system allowed the dock to accommodate different Apple devices through the use of Universal Dock Adapters, small interchangeable plastic cradles which were included with new devices as they were released, or separately in 3-packs for 9.

Releases
The Universal Dock was released in three successive versions:

2005
The first version was announced on October 12, 2005 with the iPod video and was marketed as the Apple iPod Universal Dock. It included a port and an  sensor for an Apple Remote, which was sold separately. Unlike earlier iPod Docks which were designed for specific models, Universal Dock used Dock Adapters to support a wider range of iPod models with 30-pin dock connectors.

2007
The next version's name was shortened to Apple Universal Dock following the introduction of the iPhone in 2007. It was bundled with a white plastic Apple Remote, and featured an updated design, but omitted the S-Video port. Users that wished to output video would require an iPod AV Cable that is also included with the IPod AV Connection Kit.

2010
The final version was released in 2010 and included an updated aluminum Apple Remote and new dock adapters. However, this iteration is known to have more connection issues than previous versions. It was superseded by the iPhone Lightning Dock as Apple switched from the 30-pin to the Lightning port, starting with the iPhone 5.