6N6P (6H6П) double triode from soviet production was designed for low frequency power amplification. Direct replacement for Chinese 6N6 tubes and very similar to ECC99 tubes, but with different pinout. Service life - no less than 2000 operating hours. Tubes were measured on L3-3 tube tester with original L3-3 card. Will be delivered in original boxes with measured parameters. NOS/NIB condition.