Review by Pat on 25 Dec 2024review stating Must have accessory.
Fits securely, increases the grips length perfectly to "fill" your hand, and allows you to store either AA, or CR123 batteries. It is a quality addition to a phenomenal grip. The only negative I can give is it does not create a water proof compartment for the batteries. Overall, this is a must have for the Kung Fu Grip, I will be purchasing more.