Pass through clamping grommet / wire guide. Designed in trueSpace and printed on an Up3D! printer in ABS. This wire guide was for a prototype piece of laboratory equipment (printable RTPCR module). It holds a thermocouple probe in place.
This can fit on either the outside or inside of an enclosure, glued to the surface or can go through the wall of an enclosure without the confining ring.
Scale to fit your needs. If snap fit then use drill the size of the inner diamter of the ring.