Adjustable Speaker Volume: This desk intercom speaker is loud and adjustable with clear sound. Easily mount it on the wall with tape, ideal for transmission distances up to 200 meters without interference. Perfect Combination: The indoor intercom pairs perfectly with the outdoor intercom, allowing you to talk to visitors outside your door. The doorbell sound effect is highly restored, allowing you to identify visitors outside the door by sound. 3W Power: This two-way desk intercom is designed with electro-acoustic circuit units, upgraded sound quality, and a high output of 3W for both main and sub-units, with clear and bright sound and high voice resolution. Fully Automatic Call Control: The window two-way intercom system applies fully automatic call control, with duplex voice intercom technology, automatic recognition, and processing of voice signals; the call process requires no operation. Widely Used: This window intercom system is widely used in homes, bank windows, ticket offices, hospital windows, post office windows, securities windows, embassy visa offices, securities companies, hospitals, stations, and other places where safety glass is installed.