Toolzone 6 Piece 1/2″ 3/8″ 1/2″ Drive Reducer Adaptor Set. Reducer Adaptor Set. Supplied in blow moulded storage case. Satin Finish. Add to Favourites. x1 3/4″ – 1/2″. x1 1/2″ – 3/8″. x1 1/4″ – 3/8″.