Help me identify this part

[ModernMuseum]

This part (on the right) came in the package from American Power Train. It's part of a hydramax hydraulic clutch setup for an Ls7 clutch/t56 magnum (will be mated to an LS3).

It looks awfully like the slave bearing already shown on the left. Do I need this part? Does it go in place of the one already installed for extra "height?"

It has a little ridge on the collar (as shown) that the bearing on the left doesn't have.

[camcojb]

looks like a standard mechanical throwout bearing; wouldn't be used with a hydraulic kit. No idea why they included it.