Item looks to have been adapted for bench top use Sindanyo high temperature insulation boards are manufactured from cement based products, reinforced with selected fibres. They have been specifically designed to provide excellent service under demanding thermal and electrical applications. Sindanyo is a non-asbestos, non-combustible product that is easily machined. This insulation board is a popular option when a high quality, strong and rigid material is required.400/500 Volt, 5 amp, 50 Hz 3-phase balanced load. Circular scale with lead and lag markings and graduations. The 22cm diameter meter rear-mounted to black sindanyo board, supported by wood brackets on wood base. Five terminal posts on panel below meter. Wire connections at rear. No maker's name Patent Number: 162471/20 Serial Number 263475scientific instruments, power factor maker, lead and lag markings, terminal posts, power factor meter, wire connections, sindanyo board, non-combustible, insulation, electrical applications