BACKUP O-RING, MATERIAL BUNA-N, FOR USE WITH AS568A DASH NO. 143, THICKNESS 0.053 IN, RADIUS 0.129 IN, AXIAL THICKNESS 0.045 IN, ACTUAL WIDTH 0.086 IN, ACTUAL INSIDE DIA. 2.456 IN, CROSS SECTION SHAPE RECTANGULAR, DUROMETER 90A, DUROMETER (HARDNESS) RATING HARD, COLOR BLACK, TEMP. RANGE -40 DEGREES TO 250 DEGREES F, PACKAGE QUANTITY 50