Sirui KS-40 Low Gravity Ball Head Flash Batteries The lens consists of 21

The lens consists of 21 elements in 15 groups

The Phase Fresnel element nearly eliminates chromatic aberration on its own

the lens is weather-resistant

19 Elements / 15 Groups

Linear focus is available in either rotation direction when using compatible Z series cameras

Sirui KS-40 Low Gravity Ball Head Flash Batteries The lens consists of 21Low Gravity Series Ball Head Rotating the knob to hug the ball design not only reduces the center of gravity, but also ensures the locking force. All four ball heads have the friction adjustment function to adapt various equipment with different weight. The ball head can keep stable even when heavy equipment is mounted on it. And the friction level can be kept after adjusting for much easier and more flexible operation. Suitable for Equipment with