A molding unit ( 1 ) for blow molding a container from a parison, said container comprising a wall portion and a base, said molding unit ( 1 ) comprising: - a mold sidewall (2) extending along a main axis (X) and having an inner molding surface (3) defining a counter print of the wall portion of the container, and an opening (8) at a lower end of the inner molding surface (3), - a cylinder jacket (10) fixed to the mold sidewall (2) and extending axially below the opening (8); - a movable mold base (14) having a cylindrical bracket (17) slidingly received within the cylinder jacket (10) and a body (15) axially protruding from the bracket (17), - a wear ring (33) fixed to the mold base (14), said wear ring (33) including a cylindrical guiding bushing (34) interposed between the bracket (17) and the cylinder jacket (10).