This uncoated ferrite ring magnet weighs 10g and has a pull force of 0.4kg. GradeY30BH. It has an outside diameter of 27mm, inside diameter of 13mm and is 5mm thick. Its direction of magnetization is through height.  

This ferrite magnet plays a crucial role in the functioning of a loudspeaker by creating the magnetic field needed for converting electrical signals into sound. The ferrite ring magnet is a specialized magnetic component integral to the speaker's performance. Its role is to create a stable magnetic field that interacts with the voice coil, converting electrical signals into mechanical vibrations that produce sound. The specific dimensions and magnetic characteristics of this magnet make it highly efficient in this role. Its Y30BH grade indicates a high-quality ferrite material that provides strong and consistent magnetic fields necessary for high-fidelity audio reproduction. 

This magnet is uncoated, which helps in maintaining the raw magnetic properties without interference from coatings. The direction of magnetization through the height of the magnet ensures that the magnetic field is optimally aligned with the voice coil, enhancing the efficiency and clarity of the sound produced. The ferrite ring magnet can securely interact with the other components of the speaker without dislodging, even under high-frequency vibrations.  

This ferrite ring magnet's dimensions and properties also make it useful in other applications requiring stable and precise magnetic fields. It can be used in magnetic resonance imaging (MRI) devices, sensors and a range of products that rely on consistent magnetic performance. The lightweight and compact design of the make it a versatile component in modern equipment. 

Ferrite magnets are durable and reliable, with a high resistance to de-magnetization and corrosion, which makes this ring magnet suitable for long-term applications in both consumer and commercial devices.