SGP's Linear Case consists of the upper frame, the lower frame, and the back panel that combine into a unique three-part case. The Linear line includes the Crystal Series with 11 colors, the Color Series with 11 colors, the Mini Series with 4 colors, and the Blitz Series with 3 colors. All of the Linear Series cases are compatible with each other, which allows you to personalize your phone with unique color combination. In addition, frames are available separately for those who already have a Linear case and want more options.