Quantity   Component name
1 × MT8888C Application Specific ICs / DTMF Receiver, Ringtone ICs
1 × attiny84 Microprocessors, Microcontrollers, DSPs / ARM, RISC-Based Microcontrollers
1 × tamura ttc-105 transformer 1:1 600ohm transfromer
1 × 3.579MHz crystal
1 × axicom 5V relay