20 and 25mm. Crush-resistant, self-extinguishing, LSF / Zero Halogen Polpropylene. Rated IP55. Use with 'Industrial' and 'Metal Clad' ranges. EN 50086 BS 4607.
20mm. Crush-resistant, PVC-coated Galvanised Steel Conduit and 10 nickel plated brass locknuts. Rated IP55. BS 50086.
Do I need to use the PVC coated Galvanised Steel version or can I use the cheaper version?