Round base ball mount features industry-standard AMPS hole pattern and measures hole spacing 1.3" x 1.3", connects to 1’’ mounts device holders containing the universal AMPS hole pattern B size ball mount base size is 59mm and included 1" rubber ball allows for connection to any B size/ 1 inch/ 25mm ball double socket arms; ball and socket technology allows for near-infinite adjustability Ball mount base plate made of powder-coated, marine-grade aluminum alloy and the ball made of rubber for durability and reliability in the most demanding environments 1" Ball mount base for electronic equipment, motorcycle/ car/ engineering machine/ tractor/ agricultural machinery/ forklift/ fish finders and More Backed by a lifetime warranty, if you have any questions about our 1'' Ball Mount, please contact us by email, we will help you solve it Strg 1'' Ball Mounts Base with AMPS Round Plate, Ball Base Mount Adapter Compatible with RAM and B Size 1" Ball Systems Double Socket Arm (Base Diameter: 63mm)