... material:NBR,VITON EPDM,Silicone... Hardness:60-90 Shore O-ring kit1.Kinds:28sizes = 376pcs2.Apply for auto,machines,air-conditioner ... ,EPDM,VITION,SILICONE,HNBR,CR,all material we can do.4.Any color,can be chose.5.Size AS568,PG series ... us if you are interested in anyone of them.. O-ring kit