The RAM-B-189-UN8-ALA1-KRU consists of a double 3.3" twist lock suction cup base, STANDARD length double socket arm, easy access retention knob and universal spring loaded X-Grip® cradle for 7"-8" tablets. The suction cup, twist lock base is designed to have a strong hold on glass and non-porous plastic surfaces. Included are extra easy access grip knobs, located on the back of the cradle for quick release of your tablet. The RAM-B-189-UN8-ALA1-KRU expands and contracts for perfect fit of most 7"-8" tablets with or without sleeves, as well as some smaller tablets. Please verify dimensions of your tablet below for compatibility with the X-Grip®. The X-Grip® includes a device tether recommended for outdoor applications. The cradle is compatible with handheld devices that will fit the dimensions listed below. It is important to verify the dimensions of your handheld device with a case/sleeve/skin when determining the overall size.