The United Scientific BTDR-5 borosilicate glass and PTFE bottle top dispenser has a volume range of 5 to 60mL and dispenses liquid in 1mL increments with an accuracy of + or - 0.5%. The wetted parts are borosilicate glass and PTFE (polytetrafluoroethylene). Borosilicate glass is resistant to many chemicals, thermal expansion, shock, and heat, while PTFE offers high strength and resistance to moisture, temperature, thermal expansion, and flame. This bottle top dispenser has a thread size of 30mm for attaching to a lab bottle, and it includes adapters with 28mm, 32mm, 36mm, 40mm, and 45mm thread sizes for versatility. It comes with one borosilicate glass media bottle. This dispenser is used for liquid handling applications in scientific laboratories and classroom settings.