Summary

M20 cable gland ventilator / pressure equalization insert. If you have a waterproof outdoor electronics box, and want to avoid build up of over pressure or under pressure within the enclosure, but don't want to pay for and wait for a proper ventilator with a PTFE membrane that keeps water out, this insert is an alternative. Just contains a 1mm air pipe labyrinth which will probably keep most things out under normal circumstances if pointed downwards.