Vtg Speco Tester Model YT-57 - Components Specialties No. 6810. Sold as is and as pictured untested, the top case will come off whoever I have not taken this off… please see pictures as I did notice some corrosion of a few coils, vintage item made in Japan. It is Sold just as pictured and described for parts only (although it could work, I cannot confirm). Unique device number