When using larger than standard (4 - 6mm O.D. cable) with an NC3FXX or NC3MXX (or any of the other pin configs: 4, 5, 6, 7), check out this boot. Large bushing with chuck type strain relief for XX-Series.
Accommodates cables up to an OD of 8 - 10mm
For standard sizing, in a variety of colours, check out the rest of the BXX range