Features: ---Fits rails from 0.625" - 1.25" in diameter: Also fits flat edge or square posts up to 1.25" ---Molded to the clamp is a 1" rubber ball -fits RAM B size socket arms ---Standard (medium) size double socket arm - overall length: 3.73"; socket to socket: 3" ---Curved extension base with 1" rubber ball - Mounting section of plate is 2.5" square with predrilled holes for many different screw hole patterns, including the universal AMPS hole pattern ---The connection section extends approximately 2.25" forward, at a 45 degree angle, from the center of the 1" ball and approximately 1.5" above the 1" ball (to the bottom of the connection section of the plate).