The MAX Tip provides a secure and comfortable fit in your ear, and prevents feedback (whistling). Your purchase of the iHearMAX comes with a 1-month supply of assorted tip sizes. You will need to determine the correct size for your ear before you order more. The MAX Tip lasts about 30 days, and costs about $1.50 each, or $3.00 per pack which contains 2 tips. These packs are available for purchase through our online store.