Rectangular plate features industry-standard AMPS hole pattern and measures hole spacing 2.52" x 1.51", connects to 1’’ mounts device holders containing the universal AMPS hole pattern Included B size 1" rubber ball allows for connection to any B size double socket arm; ball and socket technology allows for near-infinite adjustability Ball base mount compatible with RAM and 1" Ball Systems from Arkon, iBolt and Tackform Enterprise Series or any other 1 inch / 25mm / B size industry standard compatible mount. Ball mount base made of powder-coated, marine-grade aluminum and high-strength composites for durability and reliability in the most demanding environments Backed by a lifetime warranty, if you have any questions about our 1'' Ball Base, please contact us by email, we will help you solve it Strg 1'' Ball Mounts Base with Rectangle Plate, Ball Base Mount Adapter Compatible with RAM and B Size 1" Ball Systems