Each piece is designed to locate on either the bearing or the suspension knuckle bore/outter diameter which prevents it from slipping off.  They will also keep the knuckle and the bearing/seal square during installation.

Another feature is that when removing the respective bearings each piece will allow the bearing to pushed out completely in one go  (the bearing will go into the bore of the "anvil").

The tool will remove the knuckle bearings, dog bone bearings and the lower shock bearing.   The other piece will install these same bearings to the correct depth by simply pushing upto the shoulder on the tool.

Also included is a length of M10 studding and two nuts and washers for those that do not have a hydraulic press.   This allows a more controlled pressure to be applied to the bearing being installed than can be applied using a vice or hammer.