I am connecting an swa cable to extend a power connection from the garage to a shed/workshop. The fittings will be protected from direct water access.
I had the same question, so I did a bit of research and found that they are both made to fit into a 20mm cutout, hence the name.
20S will take a cable of 16mm maximum outside diameter and 11.6 maximum inner PVC diameter.
20L (or 20) will take up to 20mm outside diameter and up to 14mm inner PVC diameter.
Choose the smallest one that will fit your cable.
Date published: 2016-10-27