This is Cecil's Knife Trap from "SAW 4".  This is an EXTREMELY incredible prop in person, and photos alone show just how incredible this item is.  This is the "hero" blood tube unit, used as Cecil first starts pressing his face into the knives and you see the blood starting to run.  This happens from the tubes placed within the base of the unit, and then pumped up through the stand and out through the back of the knives. 

The chair itself is the "hero" chair, and is not the collapsable one as seen at the end of the scene.  This is the solid chair that Cecil sits in for the majority of the scene. 

Complete traps from the "SAW" series are not widely available.  The people who are officially auctioning the "SAW" items now have a policy of actually breaking or tearing down the complete traps, and selling them in tiny sections.  They do this with ALL the traps they get now and a complete trap will never be available again.  The COA I have on this item is a copy of the original, as I gave the original COA away when I sold the collapsable unit.  COA from Twisted Pictures.