... LSB is a mannufacture specially produce the o-ring,x-ring. Material are :FFKM,NBR, HNBR,EPDM,SI ... conditioning, etc.3. Main products: O-Ring.X-Ring V-Ring.R-Ring. Y-Ring.U-Ring., Oil Seal,PU oil seals , ... white,black ,blue ,yellow,green ,brown ,etc.7. Standard:AS568,DIN3771,JIS B2401,ISO3601,BS1806.8. accept sample or ... be make on your requirement ,but o-ring's mold fee is free. KTW standard rubber seal