Is there an alternative for 1239/20/1, Round, 20mm, 1 Way Entry, Light Duty Junction Box?
Yes, however the alternatives may vary in style, material or number of entries.
The closest alternative in galvanised cast iron is a Junction Box, Round- 20mm I.D, 1 Way Entry, Heavy Duty. The Part number is 1239H20/1.
The closest alternative in PVC is a Junction and Adaptable Boxes PVC- 20mm Entries, 1 Way. The partn number is 240/20/1.