Vanguard SBH-250 Magnesium Alloy Ball Head with Two Duel Bubble Levels + FREE Two Extra Replacement Sliding Quick Shoes Plates for All Metal Camera Tripod Magnesium alloy Head is Extremely lightweight but very strong Precision engineered center ball ensures smooth, seamless movement The fine tuning knob precisely adjusts the fiction of the ball Supports up to 44 lbs./10 kg. Includes 2 free Quick shoes