Abstract: The present invention relates to a High-heat-delivery device suitable for use in an hair straightener, a hair curling iron or an ironing apparatus and suitable for heat transfer to a substrate by direct contact with said substrate, comprising at least one element (A) having a heat transfer contact surface area, wherein the element (A) comprises a thermo-conductive thermoplastic polymer composition comprising: 30 to 89 wt % of a polyester with a Tm of at least 170° C. as measured according to ISO 11357-1/3 (2011) with a scan rate of 10° C./min; and 10 to 50 wt % of glass fibers; and 1 to 40 wt % of a thermo-conductive additive, wherein the weight percentages are based on the total weight of thermo-conductive thermoplastic polymer composition of element (A).