This is a psd file of flat UI kit, includes a a lot of useful widgets for your web design.

Name: Flattastic Flat User Interface Kit PSD
Homepage: Vlade Dimovski
License: Creative Commons Attribution 3.0
File Type: PSD
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