Audioquest - Noise Stopper Caps
Extraneous and unwanted RF / EMI signals are everywhere. Cell phones, computers, microwave ovens, and other devices spew these sources of electrical noise that highly sensitive audio and theater components can pick up.  The AQ Noise-Stopper caps are grounding plugs (not shorting plugs) that help you block out this unwanted noise. Just slip a cap over the open inputs on the back of your components. AQ Noise-Stopper caps lower the noise floor and allow your equipment to perform to it's fullest potential.