Optional RKW caster kit and NEW! heavy duty RKW-HD caster kit available * Optional RK-GDx smoked, tempered glass door available (x = total number of rackspaces) * Optional RK-RRx rear rackrail available (x = total number of rackspaces) * Optional SH-BRK Quick-PositionTM shelf mounts without rack screws, BRK models only*