Economically priced, these bottle top dispensers work perfectly for all your chemical dispensing needs. Made of PTFE and borosilicate glass for maximum chemical resistance, including acids. The dispensers featurea 30 mm thread and come complete with five additional adapters (sizes 28 mm, 32 mm, 36 mm, 40 mm, and 45 mm). They are fully autoclavable and work with most laboratory bottles. Each dispenser is individually calibrated and certified in an ISO 17025 accredited laboratory in accordance with ISO 8655 standards. 1 year warranty.