This is a super popular YL acoustic driver D-55000. The sense of density and omission in the midrange is reminiscent of a field-type tone. There are small scratches and paint peeling on the whole (Tetsuji Oikawa)
Maintenance information: 2022.6.21 operation confirmed
Accessories: None
Main specifications: driver for medium tone Playback frequency 150~7,000Hz 8Ω (measured DC resistance 9.1Ω/9.8Ω) Output sound pressure level 102dB/W/m Titanium diaphragm 140ΦXD118mm 6.3 kg/book