A composition comprising: an organopolysiloxane, a filler present at a concentration of 80-95 wt% of the composition weight and a filler treatment agent, comprising a mixture of two organopolysiloxanes having the general formulas and R 1 R 2 R 3 Si-[(CH 2) n1 (Me 2 SiO) m1] r -[O-(Me 2 SiO) m3] p -(Me 2 Si) o (CH 2) n2 (Me 2 SiO) m2 -(CH 2) n3 -Si(OR 4) 3 wherein 'Me' is methyl group, R 1, R 2 and R 3 are independently selected from an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, an alkoxy group having 1 to 3 carbon atoms or -(OSiR 7 R 8 R 9), in which R 7, R 8 and R 9 are independently selected from an alkyl group having 1 to 4 carbon atoms, R 4 is an alkyl group having 1 to 4 carbon atoms, n1, n2, m1, m3 and o are integers from 1 to 200, m2, n3, r and p are integers from 0 to 200, r and p are not 0 at the same time, (R 5 O) 3 Si-[(CH 2) n1 (Me 2 SiO) m1] r -(CH 2) n4 -[O-(Me 2 SiO) m3] p -(Me 2 Si)o- (CH 2) n2 -(Me2SiO) m 2 - n 3 -Si(OR 6)3 wherein R 5 and R 6 are an alkyl group having 1 to 4 carbon atoms, n1, m1, m3, o and n2 are integers from 1 to 200, n3, n4, m2, r and p are integers from 0 to 200, r and p are not 0 at the same time. an organopolysiloxane, a filler present at a concentration of 80-95 wt% of the composition weight and a filler treatment agent, comprising a mixture of two organopolysiloxanes having the general formulas and R 1 R 2 R 3 Si-[(CH 2) n1 (Me 2 SiO) m1] r -[O-(Me 2 SiO) m3] p -(Me 2 Si) o (CH 2) n2 (Me 2 SiO) m2 -(CH 2) n3 -Si(OR 4) 3 wherein 'Me' is methyl group, R 1, R 2 and R 3 are independently selected from an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, an alkoxy group having 1 to 3 carbon atoms or -(OSiR 7 R 8 R 9), in which R 7, R 8 and R 9 are independently selected from an alkyl group having 1 to 4 carbon atoms, R 4 is an alkyl group having 1 to 4 carbon atoms, n1, n2, m1, m3 and o are integers from 1 to 200, m2, n3, r and p are integers from 0 to 200, r and p are not 0 at the same time, (R 5 O) 3 Si-[(CH 2) n1 (Me 2 SiO) m1] r -(CH 2) n4 -[O-(Me 2 SiO) m3] p -(Me 2 Si)o- (CH 2) n2 -(Me2SiO) m 2 - n 3 -Si(OR 6)3 wherein R 5 and R 6 are an alkyl group having 1 to 4 carbon atoms, n1, m1, m3, o and n2 are integers from 1 to 200, n3, n4, m2, r and p are integers from 0 to 200, r and p are not 0 at the same time. wherein 'Me' is methyl group, R 1, R 2 and R 3 are independently selected from an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, an alkoxy group having 1 to 3 carbon atoms or -(OSiR 7 R 8 R 9), in which R 7, R 8 and R 9 are independently selected from an alkyl group having 1 to 4 carbon atoms, R 4 is an alkyl group having 1 to 4 carbon atoms, n1, n2, m1, m3 and o are integers from 1 to 200, m2, n3, r and p are integers from 0 to 200, r and p are not 0 at the same time, (R 5 O) 3 Si-[(CH 2) n1 (Me 2 SiO) m1] r -(CH 2) n4 -[O-(Me 2 SiO) m3] p -(Me 2 Si)o- (CH 2) n2 -(Me2SiO) m 2 - n 3 -Si(OR 6)3 wherein R 5 and R 6 are an alkyl group having 1 to 4 carbon atoms, n1, m1, m3, o and n2 are integers from 1 to 200, n3, n4, m2, r and p are integers from 0 to 200, r and p are not 0 at the same time.