These are simply Cage Flange Plates made to SCORE pass through Spec's, perfect for body areas where they are required to be bolted through the body and sandwich the body. They are 3/16" thick and have 7/16" holes for the bolts. Consult your Class rules, they are not required for every class! These are different than most of you are used to using, they have a hole in them. It is not for running the tube through but if you can figure out how to do it and then tie back into the frame I believe it would be legal. At least that is my take on the rulebook and we all know that everything is up for interpretation. The large holes are for shear strength. you should put the tube 2/3 through and weld the inside to the plate, weld the outside also around the tube. The additional side support of the tube adds significant shear strength when compared to a tube butt welded to a plate. These are also legal for use in the BITD Series and if they are not yet required by the series you are racing they will be as rules are modernized. These are sold in pairs to meet SCORE requirements.