They are made of PET or glass, there are no additive tube, PT tube, ESR tube, Heparin tubes, EDTA tubes, Oxalate tubes, Pro-coagulation tube, Gel and clot activator tubes, they are widely used in hospital and laboratory, We have passed ISO9001, ISO13485, and have got CE certificate. they are high quality and competitive price. if you have such request, please don't hesitate to contact me.