The Sony a7S Baseplate from SHAPE is designed to be used in conjunction with SHAPE's a7S Cage. It features two 15mm rod ports and a quick-release V-lock mounting interface. To make your a7S Cage compatible with the quick-release interface, a V-lock delta plate adapter comes included that installs underneath the cage. With the cage mounted, the baseplate's design places the optical center of camera between the two rods and the lens at a height suitable for use with a matte box. A pair of 10" long 15mm rods are included.