The 4-hole 20mm AMPS mount of 6061-T6 aluminum alloy material with CNC machining and iii grade hard anodized surface for durability and reliability in the most demanding environments. This 20mm ball mount the standard 4-hole 51mm x 43mm configuration compatible with 3rd party AMPS plates and Bulletpoint Mounting Solutions mounting arms. 20mm ball mount is wrapped by high quality anti-slip rubber, ball joint part can be rotated 360 ° ，easily attach mounting arms or device holders to the sturdy integrated 20mm AMPS ball dash mount for unmatched adjustability. NOTE:1 inch ball mount offers lifetime warranty