3 inches in length.Compatible with RAM mounts and xsaaczm any B-size 25mm/1'' spherical dual socket arms and brackets,It can also be used for expanding GPS devices,camera mounts,bicycle mounts,motorcycle phone mounts 1inch/25mm to 25mm double ball adapter is made of aluminum alloy material,and is connected by an aluminum alloy rod.Durable and resistant to rust The double ball adapter adopts rubber wrap design,reducing the friction caused by the double socket arm on the ball head(Including replaceable rubber rings) 1" ball adapter ball can be used for expanding GPS devices,GoPro,camera mounts,bicycle mounts,motorcycle phone mounts.It is very suitable for outdoor cycling and photography Through dual ball adjustment,you can flexibly rotate the device 360 degrees.Ball socket technology can achieve almost infinite adjustability 1'' Ball/25mm Aluminum Alloy Double Ball Adapter Compatible with RAM Mounts and xsaaczm any B-size 25mm/1'' Spherical Dual Socket Arms and Brackets Dual Ball Adapters Are Used for Camera Mounts,Bicycle Mounts,Motorcycle Phone Mounts,and Expansion of Gamin GPS Devices Through Dual Ball Adjustment.You Can Flexibly Rotate the Device 360 ° ,Ball Socket Technology Can Achieve Almost Infinite Adjustability