Power Attenuator G.B. II, supports up to 100W with headphone output. - Model: G.B. II - Color: Green - Maximum Output: 100W - Impedance: 8Ω - Connections: Headphone output, speaker input. This device connects between a tube amp head and a speaker cabinet to reduce output. It's a power attenuator compatible with tube amps. You can enjoy the drive of your tube amp at low volumes at home. - Included: Unit only. Thank you.