This is a 600-type desktop telephone manufactured by NEC (Nippon Electric) in 1972, based on specifications from the former Dendenkosha (now NTT). The dial speed is 20 PPS. Currently, it can only be used with dial-up lines. Please note that it cannot be used with push-button lines. However, it can still receive calls on push-button lines. Although it's over 50 years old, it's in good condition. The dial has been disassembled and serviced. As indicated on the telephone's base plate, the 600-A2(G) is a 600-type telephone, with a dial speed of 20 PPS, and (G) represents green. The dial instruction card originally had two red lines, but I didn't have one, so I used a black two-line card for 10 PPS. The 600-type telephone was developed in 1963 to replace the conventional No. 3 and No. 4 type telephones, aiming for thinner city cables, improved call quality, maintainability, and cost-effectiveness. It was designed to be lighter, with better call quality, and improved economics and maintenance compared to previous models. It consists of an N60 circuit network, a D61(G) dial, a T60 transmitter, an R60 receiver, an induction coil, and a Z60 terminal board. However, when connecting to a public line, a Z60 terminal board, a modular rosette (MJ2S), and a modular cord are required. I will be happy to advise you after purchase. If you are interested, please take a look. Thank you for reading to the end.