The present invention relates to a crosslinked polymer composition, which is obtained by crosslinking a polymer composition, which polymer composition has a melt flow rate (MFR) of at least 1.7 and comprises a polyolefin, peroxide and sulphur containing antioxidant, characterized by that the crosslinked polymer composition has an Oxidation Induction Time, determined according to ASTM-D3895, ISO/CD 11357 and EN 728 using a Differential Scanning Calorimeter (DSC), which Oxidation Induction Time corresponds to Z minutes, and comprises an amount of peroxide by-products which corresponds to W ppm determined according to BTM2222 using HPLC, wherein Z1≤Z≤Z2, W1≤W≤W2, and W≤p−270*Z, wherein Z1 is 0, Z2 is 60, W1 is 0 and W2 is 9500, and p is 18500; and use thereof, a power cable insulation and a power cable, useful in high voltage (HV) and extra high voltage (EHV) cable applications direct current (DC) applications.