Clear watch glasses are used for weighing and drying small amounts of material. These watch glasses are perfect for science project displays where you need to display minerals, insects, crystals and many other materials.
Pairs of these watch glasses can be connected to each other to simulate different types of lens. This specially works when you fill up the space between two glasses with a clear liquid such as water.
The diameter of each watch glass is 75 millimeters (about 3 inches)