This is a 15 cm unit from Vienna Acoustics. The model number and details are unknown. I was able to confirm the sound output, but it's junk because there is a crack in the center dome (Kobayashi Hitoshi)
Maintenance information: 2024.6.8 sound confirmation (center cap cracked.
Accessories: none
Main specifications: external dimensions: diameter 150 x height 80 mm, weight approx. 1.2 kg/1 bottle (actual measurement)