A combustor assembly for a gas turbine engine, the combustor assembly comprising: a liner (82, 84) having an inner wall and an outer wall spaced apart from the inner wall to define a gap therebetween, the liner (82, 84) at least partially defining a combustion chamber; an inner opening defined by the inner wall; an outer opening defined by the outer wall, the outer opening defining an internal diameter and being substantially concentric with the inner opening; a boss defined by the inner wall and extending around the inner opening and into the gap; a ferrule defining an axial direction and a radial direction perpendicular to the axial direction, the ferrule comprising: a body extending along the axial direction through the outer opening and defining a central bore in fluid communication with the combustion chamber, wherein the body has an outer diameter that is smaller than the internal diameter of the outer opening such that the ferrule can move along the radial direction relative to the outer wall; and a radial flange extending from the body along the radial direction, the radial flange being positioned within the gap and defining a flange diameter that is greater than the internal diameter of the outer opening, wherein the combustor assembly further comprises a stop ring positioned around the outer opening of the outer wall, and characterized in that the stop ring defines an annular surface extending along the axial direction, and wherein a gap height is defined between a bottom surface of the stop ring and a top surface of the boss along the axial direction, the gap height being substantially equivalent to a height of the radial flange along the axial direction such that movement of the ferrule along the axial direction is restrained. a liner (82, 84) having an inner wall and an outer wall spaced apart from the inner wall to define a gap therebetween, the liner (82, 84) at least partially defining a combustion chamber; an inner opening defined by the inner wall; an outer opening defined by the outer wall, the outer opening defining an internal diameter and being substantially concentric with the inner opening; a boss defined by the inner wall and extending around the inner opening and into the gap; a ferrule defining an axial direction and a radial direction perpendicular to the axial direction, the ferrule comprising: a body extending along the axial direction through the outer opening and defining a central bore in fluid communication with the combustion chamber, wherein the body has an outer diameter that is smaller than the internal diameter of the outer opening such that the ferrule can move along the radial direction relative to the outer wall; and a radial flange extending from the body along the radial direction, the radial flange being positioned within the gap and defining a flange diameter that is greater than the internal diameter of the outer opening, a body extending along the axial direction through the outer opening and defining a central bore in fluid communication with the combustion chamber, wherein the body has an outer diameter that is smaller than the internal diameter of the outer opening such that the ferrule can move along the radial direction relative to the outer wall; and a radial flange extending from the body along the radial direction, the radial flange being positioned within the gap and defining a flange diameter that is greater than the internal diameter of the outer opening, wherein the combustor assembly further comprises a stop ring positioned around the outer opening of the outer wall, and characterized in that the stop ring defines an annular surface extending along the axial direction, and wherein a gap height is defined between a bottom surface of the stop ring and a top surface of the boss along the axial direction, the gap height being substantially equivalent to a height of the radial flange along the axial direction such that movement of the ferrule along the axial direction is restrained.