The picture that you've linked to is actually a tension wrench.
A possible problem with SFIC locks is that with the two shear lines (operating and control) you will often find that you've set some pins at the control shear and others at the operating shearline. Basically every pin is set but you can't rotate the plug. The concept behind the tension wrench you linked to is that the teeth at the end of the wrench slot into the holes at the bottom of the control sleeve and you are able to apply a tension force at just the control shearline and not at the operating shearline. This makes it a hell of a lot easier to pick to the control shearline and I'd imagine a LOT easier to impression a control key.
You can get the Peterson IC Core kit (which includes two of the wrenches - one slim, one medium, and a Peterson Slender Gem pick) from
www.lockpicks.com . It's pretty steep in price for what you get and in my opinion you're better off just buying a Slender Gem on its own and making you're own customised wrench for the control sleeve.
