Bendable, deformable I.C.D insulating gray sheaths for the protection of electrical cables and telephones, made from LDPE resin enriched with a flame retardant product which gives a good resistance to flame propagation and have resistance to crushing and shocks, according to IEC-614-1 (1994), IEC-641-1/A1 (1995) and IEC-614-2-2 (1980).