Abstract: Insulated electrical conductor and electrical insulation which includes a polyolefin as polymeric base material and a voltage stabilizer included in the polyolefin and comprised of at least one hydrolyzable alkoxy compound, which at least one hydrolyzable alkoxy compound is a liquid at a temperature ranging from about -25.degree. C. to about 140.degree. C. and has a formula:(R.sup.a O).sub.y R.sub.3--y.sup.b X-[R-X'(OR.sup.c).sub.z R.sub.2-z.sup.d ].sub.n -OR.sup.e,where R.sup.a, R.sup.c and R.sup.e are hydrocarbon groups having 1 to 18 carbon atoms; R.sup.b and R.sup.d are saturated or unsaturated, substituted or unsubstituted aliphatic hydrocarbon groups or aromatic hydrocarbon groups having from 1 to 30 carbon atoms; R is a group having a carbon skeleton including at least one heteroatom Y; O is oxygen; X and X' are elements having a valence of four; n varies from 1 to 10, y varies form 0 to 3, z varies from 0 to 2, and where R, R.sup.a, R.sup.b, R.sup.c and R.sub.