Hearing Amplifiers for Seniors and Adults Material:Medical Resin Size:1.8*1.2cm Color : Red for Right Ear ,Blue for Left Ear How to reduce feedback for this hearing amplifier? 1. Ensure the Ear Dome fits snugly in your ear canal, if it is too loose, replace with a larger ear dome. 2. Please make sure the pulling line is below, and the volume button/dial is above when you wearing it. 3. Turning down volume. Package( for one ear) 1 x Hearing Amplifier 6 x Different size Ear Domes 1 x Cleaning Cleaning Tools Brush 3 x Earwax Guard 1 x Manuel 1 x Case Package provide Detailed wearing process, and possible problems and corresponding solutions. If you have any questions during use, please feel free to contact us, our team will provide you with professional responses within 12 hours.