1. Conical shape: The conical shape of the flask allows for easy mixing and swirling of liquids, making it a versatile tool for laboratory use.

2. Wide base: The wide base of the flask provides stability, reducing the risk of accidental spills or breakage.

3. Narrow neck: The narrow neck of the flask makes it easy to control the flow of liquid when pouring or transferring it.

4. Graduated markings: The flask may have graduated markings on the side, which enable accurate measurement of the volume of liquid inside.

5. Flat bottom: The flat bottom of the flask allows it to stand upright on a laboratory bench or shelf, making it easy to work with.

6. Borosilicate glass: The flask is typically made of borosilicate glass, which is highly resistant to thermal shock and chemical corrosion.

7. Heat resistance: The flask can withstand a wide range of temperatures.

8. Chemical resistance: The borosilicate glass used to make the flask is highly resistant to chemical corrosion, ensuring that it can be used with a range of chemicals without the risk of damage or contamination.

9. Transparency: The glass material used to make the flask is highly transparent, allowing the user to see the contents of the flask clearly.

10. Autoclavable: The flask can be sterilized using an autoclave, making it suitable for use in sterile environments and applications.

11. Accuracy: The graduated markings on the side of the flask provide a high level of accuracy when measuring liquids, making it an ideal choice for experiments that require precise measurements.

12. Cost-effective: A 250ml conical flask is relatively inexpensive, making it an affordable choice for laboratories with a limited budget.

13. Durability: The borosilicate glass used to make the flask is highly durable, ensuring that it can withstand frequent use and handling without the risk of breakage or damage.

14. Versatility: A 250ml conical flask can be used for a range of laboratory applications, including mixing, heating, and titrations.

15. Easy to store: The conical shape of the flask allows it to be stored in a compact and space-saving manner, making it ideal for laboratories with limited storage space.

In summary, a 250ml conical flask is a versatile laboratory tool that offers a range of features and benefits. Its conical shape, graduated markings, and flat base make it easy to use and work with, while its borosilicate glass construction ensures its durability and resistance to heat and chemical damage. It is also a cost-effective and space-saving choice that can be used for a range of laboratory applications.