This Telephone Bill Calculator is the new product in order to accommodate to the develop of the current telephone small shops, it is s innovative designed, looks beauty, used easily, and it is suitable to the telephone small shops. 2. Features and specification: *Large LCD screen, intuitional and easy to use. *Be designed according to the <> which was issued by the national department. The performance is conform to the national standard. *Multiple rate types include: International, national, local call, special call, no charge call, forbid call and so on. Can satisfy different requirements. *Can charge by the polarity change, delay to charge or manual charge. Can perform call in charge automatically. *Automatically identify the dial number and timer error less than 1 second. *Can query the recent 11000 bills include call number, duration and charge. *Automatically add up the charge of all bills. *Modem inside, support centralized management. Can download price and upload bills remotely. *Excellent thunder resistance, excellent stabilization. Battery inside, can last work more than 96 hours without outside power. 3. Condition & Technology standard: 1)Condition: Environment: Avoid rain, dust, direct sun shine Temperature: -20o C~+40o C Relative Humidity: 10%-95% 2)Technology Standard: Timing Precision: Reversed Polarity Signal timing precision < 1 second. Double Audio receive code>>99.99% Damp≤0.5dB Interface noise level (idle)≤60 dB (A)