A blade outer air seal (100; 400; 500; 700) support for a gas turbine engine, comprising: at least one arc body configured to form part of a ring defining an axis, the at least one arc body including a first portion (110; 410; 510) and a second portion (120; 420; 520); a blade outer air seal mounting region defined at least partially between the first portion (110; 410; 510) and the second portion (120; 420; 520); and an interface feature (130; 430; 530) interfacing the first portion (110; 410; 510) and the second portion (120; 420; 520), the interface feature (130; 430; 530) being configured such that axially aligned forces are communicated between the first and second portions (110, 120; 410, 420; 510, 520) through the interface feature (130; 430; 530), bypassing the blade outer air seal mounting region, wherein the interface feature (130; 430; 530) comprises: an axially aligned intrusion into said first portion (110; 410; 510); an axially aligned protrusion from said second portion (120; 420; 520); and the axially aligned protrusion from said second portion (120; 420; 520) is received in the axially aligned intrusion in said first portion (110; 410; 510), wherein the axially aligned intrusion includes a radially outward facing sealing surface, the axially aligned protrusion includes a radially inward facing sealing surface, and the radially outward facing sealing surface contacts the radially inward facing sealing surface, characterised in that the blade outer air seal support further comprises: an axially facing surface of said second portion (120; 420; 520) extending radially inward from a base of the axially aligned protrusion; and an axially facing surface of said first portion (110; 410; 510) spaced apart from the axially facing surface of said second portion (120; 420; 520), and defining a gap between the axially facing surface of the second portion (120; 420; 520) and the axially facing surface of the first portion (110; 410; 510). at least one arc body configured to form part of a ring defining an axis, the at least one arc body including a first portion (110; 410; 510) and a second portion (120; 420; 520); a blade outer air seal mounting region defined at least partially between the first portion (110; 410; 510) and the second portion (120; 420; 520); and an interface feature (130; 430; 530) interfacing the first portion (110; 410; 510) and the second portion (120; 420; 520), the interface feature (130; 430; 530) being configured such that axially aligned forces are communicated between the first and second portions (110, 120; 410, 420; 510, 520) through the interface feature (130; 430; 530), bypassing the blade outer air seal mounting region, wherein the interface feature (130; 430; 530) comprises: an axially aligned intrusion into said first portion (110; 410; 510); an axially aligned protrusion from said second portion (120; 420; 520); and the axially aligned protrusion from said second portion (120; 420; 520) is received in the axially aligned intrusion in said first portion (110; 410; 510), wherein the axially aligned intrusion includes a radially outward facing sealing surface, the axially aligned protrusion includes a radially inward facing sealing surface, and the radially outward facing sealing surface contacts the radially inward facing sealing surface, characterised in that the blade outer air seal support further comprises: an axially facing surface of said second portion (120; 420; 520) extending radially inward from a base of the axially aligned protrusion; and an axially facing surface of said first portion (110; 410; 510) spaced apart from the axially facing surface of said second portion (120; 420; 520), and defining a gap between the axially facing surface of the second portion (120; 420; 520) and the axially facing surface of the first portion (110; 410; 510). an axially aligned intrusion into said first portion (110; 410; 510); an axially aligned protrusion from said second portion (120; 420; 520); and the axially aligned protrusion from said second portion (120; 420; 520) is received in the axially aligned intrusion in said first portion (110; 410; 510), wherein the axially aligned intrusion includes a radially outward facing sealing surface, the axially aligned protrusion includes a radially inward facing sealing surface, and the radially outward facing sealing surface contacts the radially inward facing sealing surface, characterised in that the blade outer air seal support further comprises: an axially facing surface of said second portion (120; 420; 520) extending radially inward from a base of the axially aligned protrusion; and an axially facing surface of said first portion (110; 410; 510) spaced apart from the axially facing surface of said second portion (120; 420; 520), and defining a gap between the axially facing surface of the second portion (120; 420; 520) and the axially facing surface of the first portion (110; 410; 510). an axially facing surface of said second portion (120; 420; 520) extending radially inward from a base of the axially aligned protrusion; and an axially facing surface of said first portion (110; 410; 510) spaced apart from the axially facing surface of said second portion (120; 420; 520), and defining a gap between the axially facing surface of the second portion (120; 420; 520) and the axially facing surface of the first portion (110; 410; 510).