RAM® MOUNTX-GRIP® TABLET MOUNTSUCTION CUP BASE DOUBLE BALL MOUNTING SYSTEM•Material: Power Coated Marine Grade Aluminum•Ball Size: B•Kit includes the X-Grip® Universal Holder with Ball for 7"-8" Tablets (RAM-HOL-UN8BU) a Twist-Lock™ Suction Cup Base with Ball (RAM-B-224-1U) & a Medium-Sized Double Socket Arm (RAM-B-201U)