Screw thread vial with big mouth step vial system has a larger inner diameter than conventional vials and incorporates a neck finish that is uniquely designed to allow the insert to be precisely aligned in the center of the vial. This precise alignment provides maximum sample withdrawal and eliminates any chance of missed injections.

• 40% larger opening than other vials
• Step profile automatically centers glass flange limited volume inserts
• Preassembled caps with septa, with or without vials
• Designed for Waters Alliance® autosamplers