.250'' (1/4" Actual) Buna-N O-Ring Cord Stock, 90A Durometer, 0.250" Thickness, 10' Piece, Black O-Ring Cord made of Buna-N (Nitrile, NBR) for use with a variety of fluids and hydrocarbons Durometer (hardness) of 90A For use across a wide temperature range from -40 degrees F (-40 degrees C) to 212 degrees F (100 degrees C) Made in the U.S.A. Available in various cross sections and lengths