ioGEL  ( input-output GEL) is an easy to apply optical connector treatment that is quite revolutionary in its audible improvements to any optical connection. ioGEL should be applied to any optical digital cable (this includes all glass fiber and plastic TOS link cables.) ioGEL is more than a tweak and should be necessary component for extending the performance of all optical fiber cables. What does ioGEL do?  ioGEL completes the optical connection and assures proper optical signal coupling by eliminating the air gap between the output / input diode and the optical fiber cable connector. ioGEL is a gap filling synthetic compound for the optical signal to travel through instead of air. Think about shining a flash light through the air and how the beam of light is diffuse. Now think about shining a flash light through the water of a swimming pool and how clearly defined the beam of light now appears. The optical cable treated with ioGEL will produce an improved optical signal. Without ioGEL, the optical laser beam scatters and is compromised before it ever reaches the glass fiber cable. What do you hear with ioGEL treated optical cable? The sound across the entire audible band is clear and clean as ioGEL removes all of the veiling or haze that was there before. The application of ioGEL on any plastic TOS link cables makes them sound remarkably clear like never before.     Since the late 1980s, Aural Symphonics has held the enviable reputation for building the finest optical interfaces. Our Aural Optical  fiber optic digital cable has been labeled the     "Finest Glass cable on the Planet," (When used with ioGEL optical impedance coupler).  Jonathan Scull, Stereophile Vol. 18, #3 Disclaimer: Aural Symphonics LLC has no OEM endorsement that this product will cause any digital, optical-digital or electro-optical circuitry any problems to lock digital data as a direct result of  using ioGEL or to directly void or cause to void any OEM warranty. ioGEL is a trademark of Aural Symphonics LLC