Visico™ LE4423 / Ambicat™ LE4479 is a silane crosslinkable natural compound system designed for insulation of low voltage energy cables. Visico LE4423 is a low density polyethylene, copolymerised with vinyl silane. Ambicat LE4479 is an ambient crosslinking catalyst masterbatch specially designed to be used with Visico base resins to give reduced radial shrinkage in cables. The system is highly active and crosslinks quickly at ambient conditions, in sauna or in hot water. Cable insulation with a proper mixture of Visico LE4423 (95 parts) and Ambicat LE4479 exhibits excellent thermooxidative stability. The combination is suitable for both copper and aluminium conductors. If the insulation is designed to meet the thermo-oxidative ageing demand required by IEC 60502 at 150°C in contact with copper, the addition of 9 parts Ambicat LE4479 to Visico LE4423 is recommended.