Full Width Image is a free Chrome extension developed by benwigley. It falls under the category of Browsers and specifically the subcategory of Add-ons & Tools. This handy extension allows you to constrain a single image in your browser to be full width, making it useful for implementing design mocks.

To get started, simply follow these steps:

1. Open the extensions page in Chrome and check "Allow access to file URLs".

2. Open an image from your computer in Chrome.

3. Click on the Full Width Image extension.

With just these three simple steps, your image will now be displayed at the full width of your browser window. It's important to note that this extension only affects actual images opened in Chrome and not images within web pages.

Whether you're a designer looking to visualize your design mocks or simply want to view images in a larger format, Full Width Image provides a convenient solution within the Chrome browser.