This eartip is suitable with lEMs having nozzle outer diameter of 4.6 mm to 7mm. Softears lEMs are fully compatible, and lEMs from other brands can also be used if their nozzle outer diameter falls within the specified range. As ear tips are personal hygiene items that come into close contact with the delicate skin of the ear canal upon unsealing, they may harbor bacteria. Therefore, once opened and used, returns or exchanges are not accepted. Please confirm your needs before purchasing.