A heat shield panel (20'; 24') for use in a combustor for a gas turbine engine, comprising: a hot side and a cold side; said cold side having a plurality of cooling chambers; and each said cooling chamber having a plurality of film holes for allowing a coolant to flow from said cold side to a hot side; said cold side having a front boundary wall and a rear boundary wall; a plurality of inner rails extending between said front boundary wall and said rear boundary wall; and at least one of said cooling chambers being formed by said front boundary wall, said rear boundary wall and said inner rails; and wherein; said rear boundary wall is formed by a means for metering air flow over an edge of said panel (20'; 24') and said metering means comprising a plurality of first pin arrays and a plurality of second pin arrays, and wherein each of said first pin arrays may be arranged for alignment with a turbine vane, characterised in that: each of said first pin arrays comprises a plurality of rows of pins having a first diameter and a substantially rectangular rail surrounding said rows of pins having said first diameter, said pins in a first of said rows is offset from said pins in an adjacent row, and each of said second pin arrays may be offset from said turbine vane and comprises a plurality of rows of pins having a second diameter; and said pins in one of said rows in each said second pin array is offset with respect to said pins in an adjacent row, said second diameter is larger than said first diameter, and said pins in each said first pin array are spaced apart a distance greater than a spacing distance of said pins in each said second pin array. a hot side and a cold side; said cold side having a plurality of cooling chambers; and each said cooling chamber having a plurality of film holes for allowing a coolant to flow from said cold side to a hot side; said cold side having a front boundary wall and a rear boundary wall; a plurality of inner rails extending between said front boundary wall and said rear boundary wall; and at least one of said cooling chambers being formed by said front boundary wall, said rear boundary wall and said inner rails; and wherein; said rear boundary wall is formed by a means for metering air flow over an edge of said panel (20'; 24') and said metering means comprising a plurality of first pin arrays and a plurality of second pin arrays, and wherein each of said first pin arrays may be arranged for alignment with a turbine vane, characterised in that: each of said first pin arrays comprises a plurality of rows of pins having a first diameter and a substantially rectangular rail surrounding said rows of pins having said first diameter, said pins in a first of said rows is offset from said pins in an adjacent row, and each of said second pin arrays may be offset from said turbine vane and comprises a plurality of rows of pins having a second diameter; and said pins in one of said rows in each said second pin array is offset with respect to said pins in an adjacent row, said second diameter is larger than said first diameter, and said pins in each said first pin array are spaced apart a distance greater than a spacing distance of said pins in each said second pin array. each of said first pin arrays comprises a plurality of rows of pins having a first diameter and a substantially rectangular rail surrounding said rows of pins having said first diameter, said pins in a first of said rows is offset from said pins in an adjacent row, and each of said second pin arrays may be offset from said turbine vane and comprises a plurality of rows of pins having a second diameter; and said pins in one of said rows in each said second pin array is offset with respect to said pins in an adjacent row, said second diameter is larger than said first diameter, and said pins in each said first pin array are spaced apart a distance greater than a spacing distance of said pins in each said second pin array.