Our 25mm to 20mm elbow connector allows you to configure multiple arms in unique positions to place your device exactly where you want it Length of this adapter is 2.5 inches measuring from one end of the arm to the other and made of stainless steel CNC precision machining, sturdy and durable, not easy to be damaged Use with FANAUE series mounts or any other 1-inch / 20mm / B size industry standard compatible mount With the dual ball adjustments, this mount allows you to have the flexibility of rotating your device 360 degrees. Converts a 1-inch/B Size/25mm Mount to a 20mm mounting pattern for Garmin GPS, fanaue Phone holders, or any other 20mm mounting pattern device. FANAUE 25mm to 20 mm Dual Ball adapter with a lifetime warranty, if you have any questions, please feel free to contact us