The multi-line phone billing meter RT-BP4000, equipped with large screen, can charge up to 32 phones simultaneously. With the flexible mixture of PSTN / GSM adaptors, this suite of call shop product should be the best solution for you. Features: 1) Big screen, 320 × 240, 57 dot matrix LCD 2) 26 figures and functional keys 3) Supports up to 32 phones via PSTN or GSM simultaneously 4) Supports 50,000 entries, and recent 100 days daily sums 5) Supports Internet-based communication with management system 6) Supports three modes for incoming calls: charged, time-fixed, or free 7) Supports updating of parameters, tariffs and firmware by management system 8) Supports data report on alarm, on records-full, and on preset time 9) Supports print-out of bills and records by inside printer 10) Supports self-diagnosis and correcting failure parameter automatically 11) Supports up to 8 operators in shift mode 12) Supports prepaid calls 13) Supports remote display