Filament grommet

Currently experimenting with a low-cost pop-up greenhouse as a way of improving temperature control around the large Tevo tornado frame without the need for a full closure. Clearly, potential fire risk so try this at your own peril, but this part creates a neat route through the side of the PVC greenhouse for your filament – there's not really much room for the filament inside the enclosure.

Greenhouse available from Amazon (among other sources) for around £20:
https://www.amazon.co.uk/gp/product/B01NBKWAVB/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1