It is the speaker selector of Nagata Electric Works Co., Ltd. It is a convenient model that outputs from one input to two lines or, conversely, outputs from two inputs to one system. *Cannot be used for vacuum tube amplifiers. (Fujisawa Yukishi)
Accessories: Instruction manual, original box
Main specifications: [Input/Output] 1 system (C) → 2 (A/B) or 2 (A/B) → 1 system (C) max use watt 100W (8Ω) Weight 200g