Automatic Control! Undetectable on phone line. Needs no battery, opera- tes on telephone line power. Keep a record of all your telephone calls automatically. The TT-1 connects anywhere on the phone line and will control any battery powered tape recorder that has standard microphone and control jacks. The recorder automatically starts and stops whenever the phone is used and records both sides of the conversation with excellent fidelity. Super easy one hour assembly and a manual that tells you not only how to build the kit, but how it works as well.