http://godlyke.com/maxon-guitar-effects/maxon-resissue-series-effects/overdrive-od808
The Maxon OD808 - Maxon is the company which designed and manufactured all of the Ibanez effects till about 2002. Yes they designed the Tube Screamer.
The Maxon OD808 uses the original JRC4558 IC chip which was used in the original Tube Screamer pedal.
This is an amazing pedal with a nice mid bump to clean up those flubby lows, bring out the amazing tone of your amp and tighten up your entire tone.
The Tube Screamer was made famous and known for the amazing tones it gave Stevie Ray Vaughan.
The Maxon OD808 is now being made famous by many different Metal guys on the scene today. From Adam Dutkiewicz, Cannibal Corpse, Eric Rutan... The list goes on and on and keeps growing daily.
If you are looking for the best Metal guitar tone ever - Try the Maxon OD808