I have already posted many collection of icon sets to help in your web design work. In the series I have come up with new icon Crisp Icon Set. This is a free set of icons which contains 108 pixel perfect icons. These icons are in 3 different sizes which are 16×16, 32×32, and 48×48. You can also resize these icons to meet the requirements of your web design. While resizing icons, you just need to keep the aspect ratio.
This icon set includes photoshop PSD of each icon along with a retina version, a CSH (custom shape) file, and the PNG icons.
It means you have everything you need to have for any kind of design work.
But there is a thing which you must know. You can neither sell these icons nor host it anywhere. You will also need to link back to the original designer.
License: Creative Commons Attribution 3.0 License