The icons set design by Joel Siddall. It is a fantasitc contribution than includes 200 vector-based micro icons. The download Icons set includes all icons in PSD and AI format.

Name: Handcrafted Micro Icons PSD and Vector
Homepage: Joel Siddall
License: Free for Personal and Commercial Use
File Type: PSD, AI
The PSD file extension is used for PhotoShop Designated file – native Adobe Photoshop graphic file formats that takes up less memory than uncompressed TIF files. Saves masks, layers, clipping paths, a channels with the graphic. Not a recognized import file for all programs. PSD is commercial file format