A spacing mechanism is provided for locating at least one rotatable component relative to a stationary component of a mechanical seal. The planarization material may be applied as a thin layer or film of a hardenable material to the rough, bare back side of a wafer to produce a planar surface when hardened. The user is assigned to a second, different firewall policy group automatically if monitored user activity indicates that a change in detail level of rules is necessary. Notches in the rib vertices enable rib coupling during assembly. The invention also provides compositions and kits comprising particles. A data storage device that includes the apparatus is also provided.