These are the Acer Racing Ceramic Nitride Pro Series 5 x 13mm Bearings.

FEATURES: Assembled with diamond polished super lightweight Ceramic Nitride
            Balls which do not deform under load and also insure low friction
            and low heat buildup
          Over 33% less bearing friction compared to conventional bearings
          Exclusive no contact seals for the lowest friction and best dirt
            resistance
          Lightly oiled with Acer's SIN synthetic oil that creates an ionic
            bond between the oil and bearing parts for silky frictionless
            action

INCLUDES: Two 5 x 13 x 4mm bearings

REQUIRES: Removing original bearings from kit

                                                                   jxs 01/29/07
                                                                         ir/jxs