1 Resin-impregnated or pitch-impregnated fibres (prepregs), metal or carbon-coated fibres (preforms) or carbon fibre preforms, as follows— a made from fibrous or filamentary materials specified in paragraph 25; b epoxy resin matrix impregnated carbon fibrous or filamentary materials (prepregs), specified in Dual-Use codes 1C010.a., 1C010.b. or 1C010.c., for the repair of aircraft structures or laminates, of which the size of individual sheets does not exceed 50 cm × 90 cm; c prepregs specified in Dual-Use codes 1C010.a., 1C010.b. or 1C010.c., when impregnated with phenolic or epoxy resins having a glass transition temperature (Tg) less than 433 K (160 °C) and a cure temperature lower than the glass transition temperature. 2 In this paragraph the following terms have the meaning given to them in the Dual-Use Regulation— “carbon fibre preforms”; “fibrous or filamentary materials”; “matrix”.