CR40 Alignment Tool
This tool is used to align any of the CR40 series rail sections. The kit consist of two steel rods and a machined aluminum compression cap. The metal rods fit within the "V" groove on either side of the rail to assist in aligning the rail sections. The aluminum cap has a slight taper so that as you push it over the rods, it forces the grooves into alignment.
Product page can be found here.