Functions: 1. Automatic checking of FSK/DTMF dual system. 2. Easy to install: Can be placed on the desktop and wall. 3. Maximum 50 groups for incoming call record.. 4. Maximum 16 groups of outgoing call record. 5. Real time, date, day, and caller ID display. 6. 5 levels LCD brightness adjustable. 7. Flash time adjustable. 8. Area code and PABX code setting. 9. Speaker volume adjustable. 10. Redial and hold function. Description: 1. High quality ABS material, durable for long service life. 2. Powered by telephone line, no need to install battery, energy saving and environmental protection. 3. Color: Black/White 4. Power Supply: Telephone Line Power Supply Package List: 1 * Telephone 1 * Telephone Cable 1 * Handle 1 * Handle Cable.