Modelcraft ball bearings with ptfe cover modelcraft 8x12x3 5 zz ts modelcraft grooved ball bearing 12mm od 8mm bore features a cover on both sides providing increased protection against spray water fuels and dust particles with excellent low viscosity values the increased heat resistance also allows it to be installed close to combustion engines modelcraft 8x12x3 5 zz ts grooved ball bearing 12mm od 8mm bore