A Glass Key Stopcock for a Burette is laboratory equipment used for controlling the flow of liquids. A burette is a long, graduated glass or plastic tube with a valve or stopcock for controlling the flow of liquid. The glass key stopcock is a type of valve mechanism that can be attached to the burette to control the flow of liquid.

The stopcock consists of a glass body with a valve mechanism and a handle, which is shaped like a key and is turned to open or close the valve. The glass body and valve mechanism are typically made of borosilicate glass, which is known for its resistance to heat, chemical attack, and thermal shock.

The glass key stopcock provides a leak-proof seal and is easy to clean and maintain. It is commonly used in chemistry, biology, and other scientific experiments to control the flow of liquids in glass tubes, flasks, and other glassware.