... :1) Specifications: 13mm,20mm,24mm,26mm,28mm,30mm,32mm,34mm,etc.2) Material: bromo-butyl and chloro-butyl rubber.3) Color ... : grey,red,black,green,etc.4) Cetificate:GMP, ISO systerm; test as YBB000420025) Packed in ... : ♥Butyl Rubber Stopper for Infusion Bottles,♥Butyl Rubber Stopper for Antibiotic Bottles,♥Butyl Rubber Stopper for Freeze-dry Bottles,♥Butyl Rubber ...