Two letter can be used with this logo. Can be a G or a C or both. Full vectors, this logo can be resize and colors can be changed without problem to fit your project. The fonts used are in a download file in the package.
Fonts : http://www.fontpalace.com/font-download/NeoTech+Black/
http://www.fontpalace.com/font-download/MyriadPro-Cond/
Files provided : .ai (CS6 and CS), .eps, .jpg, .png (transparent)