The present invention relates to a liquid curable silicone elastomer composition comprising an organopolysiloxane (A) comprising an organopolysiloxane (A1) containing at least 2 alkenyl groups bonded to silicon atom per molecule and having a total alkenyl content of from 0.01 to 1.5 mmol/g, and an organopolysiloxane (A2) containing at least 2 alkenyl groups bonded to silicon atom per molecule and having a total alkenyl content of from 5.0 to 15.0 mmol/g； an organopolysiloxane (B) comprising an organopolysiloxane (B1) containing at least 2 silicon-bonded hydrogen atoms per molecule, wherein said silicon-bonded hydrogen atoms are provided in the form of siloxy units of the type (R2HSiO1/2) x where R is independently selected from hydrogen, aliphatic hydrocarbyl, aromatic hydrocarbyl, or organyl group and x ≥ 2； and an optional organopolysiloxane (B2) containing at least 2 silicon-bonded hydrogen atoms per molecule, wherein said silicon-bonded hydrogen atoms are provided in the form of siloxy units of the type (RHSiO2/2) z where R is independently selected from hydrogen, aliphatic hydrocarbyl, aromatic hydrocarbyl, or organyl group and z ≥ 2, wherein the molar amount of silicon-bonded hydrogen in the form of siloxy units of the type (R2HSiO1/2) x is >；40mol% of the total silicon-bonded hydrogen atoms content of organopolysiloxane (B)； a platinum based catalyst (C)； an inhibitor (D) selected from the group consisting of acetylenic alcohols and their derivative； a silica filler (E).La présente invention concerne une composition d'élastomère de silicone liquide durcissable comprenant un organopolysiloxane (A) comprenant un organopolysiloxane (A1) contenant au moins 2 groupes alcényle liés à l'atome de silicium par molécule et présentant une teneur totale d'alcényle de 0,01 à 1,5 mmol/g, et un organopolysiloxane (A2) contenant au moins 2 groupes alcényle liés à l'atome de silicium par molécule et présentant une teneur totale d'alcényle de 5,0 à 15,0 mmol/g； un organopoly
