About free images
On this site you'll find: Stock image renders and animations of 3D models for free download, for personal or commercial use, licensed under Creative Coommons Attributtion 4.0. Just give me appropriate credit of authorship and done!
PNG format with transparency: Most images are in PNG format with alpha channel, for quick easy integration in your compositions, blogs, web or even games! (Animations provided in GIF format)
Access to original 3d model file: Bellow each image click the link to see more details about the source file format fromTurboSquid.