Abstract: This invention relates to an improved spirally wound flexible tube of the type having an inner electrically conductive plastic strip of channel shaped cross-section including a relatively wide flat web and flexible flanges bordering the margins of said flat web, the inner strip being helically wound to form a tube with the flanges directed radially outward and arranged in contiguous pairs with each succeeding convolution; and an outer nonconductive plastic cap section of channel shaped cross section helically wound over the inner plastic strip, the cap including a relatively narrow web having flexible flanges directed radially inward and overlying the contiguous pairs of radially outwardly directed flanges and bonded through the distal side.