Good conclusion: the natural cork has an excellent tightness. It provides a good barrier against outside air and liquids and prevents the filling of the tube from escaping. They can also be used in classroom, medical field, laboratory and chemical industry. High Quality Material: The transparent test tube is made of high quality glass, which is strong and non-. The bottom of the test tube is smooth, the thickness of the test tube wall is uniform, the transparency is high, and it is not easy to break. It can be reused after cleaning. Test Tube Set: 60pcs 2 x 15cm Glass Test Tube with Cork, 80PCs Heart Shaped Paper Tags, 10m Jute Rope, 4 Funnels. Enough to meet your multiple needs. DIY Filling: This flower test tube jar can help you achieve various DIY filling decoration. You can use test tubes to store liquid, fill powder, candy, grain, beads, , dried flowers, seeds, coffee beans, etc. decorations and gifts: this test tube is very suitable for decoration and gifts of various parties, such as children's baptism, birthday, wedding, Halloween, Christmas party, etc. You can put your favorite candies or other filled test tubes on the party table and room decoration, and of course, you can also give blessings as gifts for family, friends, guests, etc.