The W6-UNI amplified handsets improve listening volume up to 20dB for clearer reception. The W6-UNI amplified handsets are for added receiver volume in noisy surroundings, poor line quality and for the hearing impaired. The W6-UNI are universally compatible with carbon, electret or dynamic transmitters. The W6-UNI is compatible with virtually any telephone with a K-style handset. It solves compatibility issues and simplifies ordering.