... net backing disc, for making flap disc, to match ISO standard Type:T27(Flat) ,T29(Convex) fiberglass net backing disc, for making ... flap disc, to match ISO standard Types and dimensions(According to ISO15635:2001): d±3 /mmH ... .610522,23454,611522.23454.614022,23454,617022,23454,6Product description:Type:T27(Flat) ,T29(Convex)Material: Fiberglass fabric impregnated with ...