A Burette with a screw-type rotaflow stopcock is laboratory glassware used for measuring and dispensing precise volumes of liquids. The burette is a long, cylindrical piece of laboratory glassware with a graduation scale used for measuring the volume of liquid.

The screw-type rotaflow stopcock is a type of valve located at the bottom of the burette that controls the flow of liquid. It is adjusted by turning a screw-type knob, allowing for precise control of the flow of liquid, and ensuring that the correct amount is dispensed.

The screw-type rotaflow stopcock provides consistent and accurate flow control, making it ideal for use in chemical and biological experiments where precise liquid measurements are required, such as titrations. The burette and rotaflow stopcock are typically made of durable, chemically-resistant glass, and can be used for a wide range of applications.