A twin axial cable includes a pair of wires each with a core conductor; a first dielectric extruded around each of the core conductors, said pair of conductors with the first dielectrics being intimately side by side positioned with each other in a transverse direction; a second dielectric different form the first dielectric and extruded around the first dielectrics; a shielding layer enclosing the second dielectric; and a heat seal PET layer enclosing the shielding layer. A coupling ratio which is calculated by a value of an even mode characteristic impedance subtracted an odd mode characteristic impedance divided by a value of the even mode characteristic impedance pulsed the odd mode characteristic impedance is between 15% to 30%.