1)non-toxic,no posion,good smell. 2)It meets ISO9001-2000standard ... produce various kinds of O-ring : Rubber O-Ring ,O-Ring Seal , Rubber Product ,Rubber Part ,Silicon O-Ring.Various types are available according ... of Silicon, Rubber,NBR,NR,EPDM,SBR,IIR,CR materials,non-toxic,no posion,good smell,safetly.2)Excellent waterproof and ...