This is a MOLEXT (Molex On The Move), a portable battery-powered Molex power adapter from around 2011.
It was designed primarily for mobile Xbox 360 modders and flashers. The device uses internal batteries (or possibly AA batteries in some versions) to provide Molex power (the standard 4-pin peripheral power connector) on the go, without needing a PC power supply or wall outlet.It allowed users to power tools like the CK3 or connect to Xbox 360 DVD drives for flashing firmware in remote locations (e.g., "parking lot modding").
The short cable in the photo ends in a female Molex connector for plugging into devices that need Molex power.It's a niche accessory from the Xbox 360 modding scene, sold by sites like XConsoles, and no longer commonly available.
The website on the label (www.molext.com) (www.molext.com)