... pen, are made of 100% high grade silicone rubber OEM orders welcome ISO9001 & TS16949 factory Silicone sleeve for pen, OEM orders are welcomeDescription ... : Material: comply to RoHS, silicone or rubber (NR, SBR, NBR, EPDM, CSM, CR, HNBR, VITON, ... can reach ±3 shore A tolerance Color: for rubber, usually black, for silicone, can be in any color as you want ...