... kits according customers requirment ,like NBR,SBR ,FKM,SILICONE o-ring kits. O-ring kits have sturdy plastic containers produced in either ... cards or labels indicating the sizes and quantities of the o-ring seals in each compartment. Should your purchase be for ... , you may note that our O-ring kits are conveniently shipped in plain boxes, with generic labeling for easy relabeling and reshipment ...