We've enhanced all of our products to be more efficient than before, and the I90 clamp is no exception. The new I90 Rod has many new great features. It is sturdier and lighter which increases its reliability and strength. The I90 has been redesigned to improve performance. It consists of a rod that allows a railblock to be attached directly to it. We have two rod size options: 12" rod and 4.5" rod. The 12" rod provides 4.5" of rod space on both sides of the center railblock and the 4.5" option provides 4.5" of rod space on one side of the center railblock, like our Austin Rig set-up. It is made of aluminum with 1/4-20 threads throughout it, which is perfect for mounting various accessories. The I-90 has an improved sleek look and yet it continues to be an economical option.