Product Description : Sirui uses Computer Aided Manufacturing CAM to produce a support ball with tolerances within 001 mm of a perfect sphere This uncompromising precision ensures superior performance and smooth operation for any type of 35 mm DLSR or medium format camera system Sirui ball heads are made of aviation quality aluminum alloy 7075-T6 and 6067-T6 for long life and maximum strength Quick release plates are made from forged aluminum alloy The forging technique produces high-density metals with much greater strength than die-cast methods The panning base is designed with a 360deg dial Having a separate panning base lock knob provides greater accuracy for panning and panoramic shooting The patented safety lock design and Sirui quick release plates effectively prevent the camera from accidentally sliding off of the ball head Most Arca-style quick release plates can be used on Sirui ball heads The custom anodized surface treatment makes all metal surfaces highly resistant to abrasions and produces a beautiful appearance