it depends on what truck you have, and how much protection you need. i bought a rollcage for my jato, it had so much wieght up hi it handled like a pig. iam getting ready to build one for my t-max, out of fuel line tubing. i bought a shock tower that had a round hole for the body mounts, that i had to drill out for 5/16 fuel tubing. dont for get all tubing is measured on the od. any way, iam planing on useing very little tubing just enough to do the job. i just saw that you are in the U.K. 5/16 in metric is 7.95 mm just for a reference.