Battery life, after installing the handle, you can install an extra battery to increase the power when . Increase the balance, the camera will lose balance after installing a lens, and the handle acts as a stabilizer. Vertical , vertical is more convenient when portraits. Protect the camera and prevent the camera from being bumped. With a dust/splash-resistant rugged design it allows for a more comfortable grip even when from vertical angles. Product model: MB-D80 Applicable models: For NIKOND80/D90 Power supply: EN-EL3e or 6 AA batteries (not included) Product size: 138 x 73.5 x 110mm Material: ABS color: Black Package Contents: 1 x Camera Handle Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.