Sitecore Content Hub provides several predefined asset renditions that you can download. You can also customize and save renditions specific to your requirements.
Using the custom download feature, you can make high-quality edits on assets and create custom renditions. It provides you with a list of preset dimensions (based on the requirements of social media websites) that you can apply to your assets. It also includes the option to crop assets manually.
By default, the download option is available on pages where you would typically download assets, such as the Assets page and the asset details page.