Unspecified set of 2 wood blocks 30mm square insulator cube It is similar to Yamamoto Sound Crafts's QB-1, but it is smaller than the QB-1 and the details are unknown. You can see the exterior, dullness, and feeling of use (Kobayashi Hitoshi)
Main specifications: W30 x H30 x D30 mm 28.6 g (actual measurement)