below a link to a manual on the or where I believe there is everything, but I procur everything, including what you look for gerod.http://www.tss.trelleborg.com/com/www/media/downloads/catalogs/o_ring_gb.pdfp.s. I confess my ignorance, so much to change, I did not know that gorges for or could be made even trapezoidals (with the major base inside)!
Bye.
