Match various models of automatic samplers such as Agilent, Waters, Varian, and Shimadzu. Made from hydrolyzed glass (Class 1 borosilicate glass) with low free ion content; PTFE/silicone pad, soft seal, very durable, optional with graduated markings and ceramic writing labels. The assembled bottle cap and pad can be used immediately. The flat bottom ensures compatibility with the inner village pipe, and the sample bottles are packaged in an ultra clean environment with a specially designed packaging to reduce pollution. Strict quality assurance provides consistency between batches.