Abstract: Double tubing comprises two flexible plastic protective tubes (1, 2), integrally joined with one another via a web (5), which are embodied as corrugated tubes. For installing the double tubing without damage and to prevent deformation of the protective tubes, and in this manner to make them particularly suitable for plumbing applications, fastening holes (11) for fastening screws (17) are embodied in the web (5). Each fastening hole (11) is embodied between two corrugation crests (3) disposed opposite one another in pairs, and in the area of the respective fastening hole (11) the crests (3) are deformed into secant-like defining walls (12) of the respective fastening hole (11).