Therefore, the 2ml snap top HPLC vial is easy to fill and increases the target area of the autosampler needle. This means that 2ml snap-top HPLC vials can protect needles. The 2ml snap-top HPLC vial size is 11.6x32mm and is compatible with most autosamplers such as Aijiren. 2ml HPLC vials are available in amber and transparent colors. Quote Now.