The Ultradyne USA® UD Orbit Ballhead with Arca-Pic Clamp features 6061-T6 aluminum and 416 stainless steel construction. Aluminum features an anodized corrosion-resistant finish while stainless steel features Nitride corrosion-resistant finish. Designed to work with Arms 17S style clamps and the Ultradyne Arca-Pic Clamp. When the Orbit Ballhead is used with the UD Chassis and UD Launchpad, users can get a full range of aiming with almost no recoil. The UD Orbit Ballhead was built with shooters in mind and features an adjustment wheel strategically located under the forearm for quick, easy access. This design feature makes it, so shooters don't have to change up their shooting style. Dimensions: 3.58"L x 2.49"W x 4.75"H. Threads: 3/8"-16" Made in USA.