Doing a little spring cleaning, and same across my 15 year accumulation of add-on ribs. In various states of use, experimentation, ect. 8 are 1/8" thick, 9 are 1/4" thick. Steel (three of the 1/4" ribs), aluminum, and plastic. One @ 24", one @ 30", and the rest are 24-25" long. $100 shipped (lower 48) for the lot)