The tablet holder is compatible with 7 to 11 inch tablets and connects to the Magic Suction Cup base through the L Size (9") Dual Knuckle Arm. This arm is constructed by linking two S size arms with a 3" extension. The four ball heads of the arm allow users to adjust the mounted tablets to precise positions that suit their special needs. The extension arm has three 1/4"-20 and two 3/8"-16 female thread holes that allow for mounting devices using an additional Super Knuckle Arm. The other end of the arm has a ball head with a hex stud that connects to the Magic Suction Cup. This 6" suction cup provides a strong but removable grip on most flat nonporous surfaces, such as glass and metal. To attach the suction cup, pump the plunger until the red line is hidden. To remove the suction cup, simply pull the rubber tab at the edge of the suction cup to break the vacuum. The user-friendly suction cup is easily secured and removed efficiently from any nonporous flat surface. This set is an ideal solution to temporarily mounting a tablet within a flexible 9" (22.8 cm) radius to a nonporous flat surface.