This is a 20GB Xbox 360 Microsoft Corporation hard drive and audio adapter. They are both silver-toned and grey in color.
The model number is X804675-003. It was made in Redmond, WA.
The hard drive measures 1.5" tall, 3" wide, and 7.5" deep.
The audio adapter measures 1" tall, 2.25" wide, and 10.75" deep.
They appear to be in pre-owned condition. They are untested and sold as-is.