The Brake Lite SA is an attenuator that works with any tube amp up to 45 watts and can be used with 4, 8, or 16, ohm loads*. The SA features 2 speaker outs that are wired in parallel. You can now run multiple cabs with ease. At the Zero setting the Brake Lite SA is fully bypassed. Each click yields more attenuation: 1=2dB, 2=5dB, 3=8dB, and 4=11dB.