I used the one it came with, bent it. Also note the use of this I-beam as bought will require a support rope. I switched to a solid bar stock to finish out the season, but will have my xop seat and I-beam drilled out to accept a 5/16" bolt. Its going to require a Bridgeport to offset the hole, not just make it bigger. Sadly I miss my I-beam already after 2 sits.