Description: Balance Armature Receiver for hearing aid 1. Excellent sound 2. Mini size 3. Low THD 4. Waterproof Specifications: 1. Speaker size: 5.18*3.6*3.0mm 2. Impedance: 120 ohm ( 3-1000ohm, can be customized) 3. Maximum output: 130db Features: 1. Outstanding efficiency 2. Substantial maximum output 3. Magnet-radiation shieded 4. Optimized mechanical shock resistance 5. Waterproof