The PAIR OF 15MM MALE-FEMALE RODS (4"), located at the back of the camera support, are used to attach the ADJUSTABLE COMPOSITE SHOULDER PAD, the BASE COUNTER-WEIGHT ROD BLOC and many other accessories.
On end is male and the other end is female.
The threads enable you to use either 4"or 8" rods (½-13").
The rods are made of lightweight hard anodized aluminum for strength and durability.